Key Financial Data Of Reporting Company
| Concept | 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 | As at 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 | — | — | 
                                                177,057,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                10,462,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                97,991,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                159,181,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                89,808,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                142,051,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                63,725,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                96,421,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                53,331,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                60,967,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | — | 
                                                27,227,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                8,310,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                16,899,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,316,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                10,881,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                16,690,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,382,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,360,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -11,487,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -19,811,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) | — | — | — | — | — | — | — | 
                                                4,281,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                9,853,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                4,221,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,540,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -9,893,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Share capital | — | — | — | — | — | 
                                                25,665,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                25,454,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                25,326,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                25,021,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                25,021,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total number of issued shares | — | — | — | — | — | 
                                                288,477,042
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                287,780,142
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | 
                                                287,358,642
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | — | 
                                                95,452,914
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | 
                                                95,452,914
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
| Net assets | — | 
                                                72,354,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                47,625,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                70,537,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                56,915,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                56,696,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                61,180,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                54,603,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                57,514,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                40,892,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                47,416,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | 
                                                213,655,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                89,831,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                185,464,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                116,414,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                115,729,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                170,623,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                157,698,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                137,623,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                150,576,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                141,026,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | 
                                                274.80
                                                
                                             | — | — | — | 
                                                180.49
                                                
                                             | — | — | — | — | — | 
                                                260.59
                                                
                                             | 
                                                210.08
                                                
                                             | — | 
                                                201.31
                                                
                                             | 
                                                217.30
                                                
                                             | — | — | — | 
                                                189.70
                                                
                                             | 
                                                199.87
                                                
                                             | 
                                                152.87
                                                
                                             | — | — | 
                                                177.38
                                                
                                             | 
| Dividend paid per share | — | — | — | — | — | — | — | 
                                                16.0
                                                
                                             | — | 
                                                12.0
                                                
                                             | — | — | — | 
                                                16.0
                                                
                                             | — | — | — | 
                                                20.0
                                                
                                             | — | — | — | — | 
                                                20.0
                                                
                                             | — | — | 
| Basic earnings (loss) per share | — | — | 
                                                59.71
                                                
                                             | — | — | — | — | 
                                                15.95
                                                
                                             | — | 
                                                36.48
                                                
                                             | 
                                                57.99
                                                
                                             | — | — | 
                                                14.75
                                                
                                             | — | — | 
                                                34.03
                                                
                                             | 
                                                12.59
                                                
                                             | 
                                                14.00
                                                
                                             | — | — | — | 
                                                -37.10
                                                
                                             | 
                                                -67.40
                                                
                                             | — | 
| Diluted earnings per share | — | — | 
                                                59.55
                                                
                                             | — | — | — | — | 
                                                15.90
                                                
                                             | — | 
                                                36.40
                                                
                                             | 
                                                57.88
                                                
                                             | — | — | 
                                                14.75
                                                
                                             | — | — | 
                                                34.01
                                                
                                             |  |  | — | — | — |  |  | — | 
| Equity-to-asset ratio | — | 
                                                0.337
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.527
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                0.379
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.487
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.488
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.357
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.344
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.416
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.270
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.335
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | 
                                                0.225
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.082
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.174
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.239
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.074
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.169
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.068
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.083
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | — | 
                                                16.50
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                61.76
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                21.57
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                13.57
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                34.64
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                15.02
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                35.75
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                32.15
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Payout ratio | — | — | — | — | — | — | — | 
                                                1.003
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.329
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.542
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.530
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                45,465,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                44,632,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                35,830,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                28,304,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -7,528,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -23,368,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                -15,356,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -11,911,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -8,473,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -6,344,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | — | 
                                                -7,219,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                -22,856,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -42,110,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -19,302,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                24,088,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                51,154,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                36,463,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                29,106,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                46,316,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                44,851,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Number of employees | 
                                                2,064
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,209
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                35
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                794
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                35
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,270
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                145
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                2,108
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,282
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1,284
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,062
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                2,105
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,287
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,772
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                1,265
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                5,671
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5,765
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                51
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,084
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                51
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                4,587
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                94
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                6,012
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                4,800
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                4,614
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5,718
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                5,033
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                4,127
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                4,496
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                3,899
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Total shareholder return | — | — | — | — | — | 
                                                5.521
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                4.379
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                2.842
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2.473
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                2.251
                                                
                                                    
                                                        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
                                                    
                                                
                                             |