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 | 2024-04-01 to 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 | — | — | — | — | — | 
                                                22,891,436,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                10,497,287,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,518,001,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                21,820,464,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                8,599,259,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                17,673,563,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,844,663,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                16,927,017,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                7,911,864,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                16,295,195,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | — | — | — | — | 
                                                650,634,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                446,251,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                559,616,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                998,561,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                441,596,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                537,868,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                70,166,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                253,122,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -192,411,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -42,641,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) | — | — | — | — | — | — | — | — | 
                                                274,233,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                256,633,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                51,157,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                43,283,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -527,966,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Share capital | — | — | — | — | — | — | 
                                                5,323,965,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                5,323,965,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,323,965,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                5,323,965,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                5,323,965,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total number of issued shares | — | — | — | — | — | — | 
                                                16,773,376
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | — | 
                                                16,773,376
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | 
                                                16,773,376
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | — | 
                                                16,773,376
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | 
                                                16,773,376
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
| Net assets | — | — | — | — | 
                                                12,999,698,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                11,611,783,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                12,724,668,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,483,236,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                11,153,059,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,128,324,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                12,059,438,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,094,178,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,960,719,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                11,114,061,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | — | — | — | 
                                                26,243,665,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                20,361,110,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                25,474,230,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                20,328,052,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                19,800,374,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,174,180,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                23,863,805,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                19,663,051,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                23,607,917,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                19,330,611,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | — | — | — | 
                                                847.71
                                                
                                             | — | 
                                                757.20
                                                
                                             | — | — | — | — | 
                                                829.78
                                                
                                             | 
                                                748.82
                                                
                                             | — | 
                                                727.28
                                                
                                             | 
                                                790.87
                                                
                                             | — | — | — | 
                                                786.37
                                                
                                             | 
                                                723.43
                                                
                                             | 
                                                779.93
                                                
                                             | — | — | 
                                                724.73
                                                
                                             | 
| Dividend paid per share | — | — | — | — | — | — | — | — | 
                                                10
                                                
                                             | 
                                                13
                                                
                                             | — | — | — | 
                                                5
                                                
                                             | — | — | — | 
                                                2
                                                
                                             | — | — | — | — | 
                                                2
                                                
                                             | — | — | 
| Interim dividend paid per share | — | — | — | — | — | — | — | — |  |  | — | — | — |  | — | — | — |  | — | — | — | — |  | — | — | 
| Basic earnings (loss) per share | — | — | — | — | — | 
                                                26.50
                                                
                                             | — | — | 
                                                17.88
                                                
                                             | 
                                                16.73
                                                
                                             | 
                                                33.91
                                                
                                             | — | — | 
                                                3.34
                                                
                                             | — | — | 
                                                3.96
                                                
                                             | 
                                                2.82
                                                
                                             | 
                                                10.69
                                                
                                             | — | — | — | 
                                                -34.43
                                                
                                             | 
                                                -21.62
                                                
                                             | — | 
| Diluted earnings per share | — | — | — | — | — |  | — | — |  |  |  | — | — |  | — | — |  |  |  | — | — | — |  |  | — | 
| Equity-to-asset ratio | — | — | — | — | 
                                                0.495
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.570
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.500
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.565
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.563
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.502
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.505
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.564
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.507
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.575
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | — | — | — | 
                                                0.0316
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.0237
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.0227
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.0418
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.0046
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.0050
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.0039
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.0136
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                -0.0464
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                -0.0273
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | — | — | — | — | 
                                                52.38
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                77.63
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                86.61
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                42.73
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                321.86
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                271.46
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                191.49
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                50.51
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Payout ratio | — | — | — | — | — | — | — | — | 
                                                0.559
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.777
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1.497
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.709
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | — | — | — | — | 
                                                -972,814,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -515,298,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -20,735,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                670,336,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                903,303,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | — | — | — | — | 
                                                64,841,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -531,092,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                47,763,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -259,086,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -51,881,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | — | — | — | — | 
                                                314,542,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                413,097,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -52,959,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                138,137,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -106,412,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | — | — | — | 
                                                2,287,813,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                2,871,016,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,500,798,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,526,326,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,975,308,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Number of employees | 
                                                301
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                474
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                301
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                474
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                484
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                305
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                295
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                472
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                527
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                314
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                580
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                356
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                64
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                85
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                64
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                85
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                88
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                61
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                64
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                89
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                87
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                62
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                77
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                50
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Total shareholder return | — | — | — | — | — | — | 
                                                8.452
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                8.756
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                6.452
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                3.238
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1.030
                                                
                                                    
                                                        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
                                                    
                                                
                                             |