Key Financial Data Of Reporting Company
| Concept | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 2023-04-01 to 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 2022-04-01 to 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | 2022-04-01 to 2023-03-31 | 2021-04-01 to 2022-03-31 | 2021-04-01 to 2022-03-31 | As at 2022-03-31 | As at 2022-03-31 | As at 2021-03-31 | 2020-04-01 to 2021-03-31 | 2020-04-01 to 2021-03-31 | As at 2021-03-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||||||||||||||||||||||||
| Business results of reporting company | ||||||||||||||||||||||||||||
| Net sales | — | — | — | — | — | — | 
                                                420,647,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                290,545,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                252,304,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                382,279,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                253,626,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                388,614,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                255,112,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                361,730,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                208,785,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                301,961,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | — | — | — | — | — | 
                                                33,051,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                23,491,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                21,192,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                26,906,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                24,547,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                31,393,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                40,597,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                49,468,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                33,154,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                38,668,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) | — | — | — | — | — | — | — | — | — | — | — | 
                                                19,927,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                30,306,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                8,490,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                28,072,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                24,239,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Share capital | — | — | — | — | — | — | — | — | — | 
                                                24,211,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                24,211,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                24,211,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                24,211,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                24,211,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total number of issued shares | — | — | — | — | — | — | — | — | — | 
                                                215,251,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | — | 
                                                229,513,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | 
                                                229,513,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | — | 
                                                237,075,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | 
                                                237,075,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
| Net assets | — | — | — | — | — | 
                                                357,992,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                247,672,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                363,729,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                268,757,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                247,899,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                339,308,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                321,836,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                240,125,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                298,246,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                229,111,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | — | — | — | — | 
                                                533,786,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                428,670,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                532,254,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                440,484,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                421,857,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                522,868,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                484,660,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                402,682,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                448,821,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                379,360,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | — | — | — | — | 
                                                1,810.79
                                                
                                             | — | — | — | 
                                                1,254.93
                                                
                                             | — | — | — | — | 
                                                1,714.88
                                                
                                             | 
                                                1,271.41
                                                
                                             | — | 
                                                1,172.91
                                                
                                             | 
                                                1,591.79
                                                
                                             | — | — | — | 
                                                1,487.33
                                                
                                             | 
                                                1,120.31
                                                
                                             | 
                                                1,349.89
                                                
                                             | — | — | 
                                                1,046.79
                                                
                                             | 
| Dividend paid per share | — | — | — | — | — | — | — | — | — | — | — | 
                                                70.00
                                                
                                             | 
                                                45.00
                                                
                                             | — | — | — | 
                                                36.00
                                                
                                             | — | — | — | 
                                                28.00
                                                
                                             | — | — | — | — | 
                                                22.00
                                                
                                             | — | — | 
| Interim dividend paid per share | — | — | — | — | — | — | — | — | — | — | — | 
                                                35.00
                                                
                                             | 
                                                20.00
                                                
                                             | — | — | — | 
                                                18.00
                                                
                                             | — | — | — | 
                                                13.00
                                                
                                             | — | — | — | — | 
                                                11.00
                                                
                                             | — | — | 
| Basic earnings (loss) per share | — | — | — | — | — | — | 
                                                127.43
                                                
                                             | — | — | — | — | 
                                                96.92
                                                
                                             | 
                                                143.43
                                                
                                             | 
                                                147.19
                                                
                                             | — | — | 
                                                40.12
                                                
                                             | — | — | 
                                                49.94
                                                
                                             | 
                                                128.73
                                                
                                             | 
                                                153.22
                                                
                                             | — | — | — | 
                                                110.84
                                                
                                             | 
                                                126.74
                                                
                                             | — | 
| Diluted earnings per share | — | — | — | — | — | — | 
                                                127.37
                                                
                                             | — | — | — | — | 
                                                96.88
                                                
                                             | 
                                                143.36
                                                
                                             | 
                                                147.12
                                                
                                             | — | — | 
                                                40.10
                                                
                                             | — | — | 
                                                49.92
                                                
                                             | 
                                                128.64
                                                
                                             | 
                                                153.12
                                                
                                             | — | — | — | 
                                                110.74
                                                
                                             | 
                                                126.63
                                                
                                             | — | 
| Equity-to-asset ratio | — | — | — | — | — | 
                                                0.669
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.578
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.681
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.610
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.587
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.643
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.657
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.596
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.658
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.604
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | — | — | — | — | 
                                                0.073
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.077
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.117
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.089
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.035
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.032
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.120
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.109
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.115
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.100
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | — | — | — | — | — | 
                                                11.7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                15.4
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                9.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                9.0
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                34.9
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                28.0
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                10.6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                8.9
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                16.0
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                14.0
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Payout ratio | — | — | — | — | — | — | — | — | — | — | — | 
                                                0.722
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.314
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.897
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.218
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.198
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | — | — | — | — | — | 
                                                20,781,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                47,413,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                14,358,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                33,140,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                56,080,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | — | — | — | — | — | 
                                                -22,026,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                -5,428,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -28,899,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -26,436,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -30,239,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | — | — | — | — | — | 
                                                -17,123,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                -30,085,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -2,820,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -11,883,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -8,259,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | — | — | — | — | 
                                                26,836,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                42,533,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                28,270,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                44,521,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                48,152,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Number of employees | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,163
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,375
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,937
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                509
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                4,493
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                860
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                663
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,532
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                518
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                4,462
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,470
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                2,370
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                4,293
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                3,981
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,107
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                3,502
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                1,642
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                59
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                93
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                123
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                164
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                456
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                81
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                75
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                304
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                165
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                454
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                291
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                260
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                429
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                416
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                251
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                414
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                240
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Total shareholder return | — | — | — | — | — | — | — | — | — | 
                                                2.084
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1.784
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1.824
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1.737
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                2.200
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Total return on share price index | — | — | — | — | — | — | — | — | — | 
                                                2.134
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2.168
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1.534
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1.450
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1.421
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |