Key Financial Data Of Group
| Concept | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | 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 group | |||||||||||||||||||||||||||
| Business results of group | |||||||||||||||||||||||||||
| Net sales | — | — | — | 
                                                10,795,074,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                10,362,419,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                9,059,300,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,707,361,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                5,262,208,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | — | — | 
                                                944,123,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                469,691,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                435,534,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                848,042,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                901,513,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                982,941,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                531,140,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                580,102,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                320,977,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                347,492,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | — | — | — | 
                                                589,094,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                516,653,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                651,476,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                413,839,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                246,644,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Comprehensive income | — | — | — | 
                                                590,457,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                514,115,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                650,698,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                413,537,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                244,837,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | — | 
                                                3,261,982,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2,721,879,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                2,824,716,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,482,806,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,257,706,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,406,496,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,712,917,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,586,298,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,498,744,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,400,039,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | — | 
                                                6,508,220,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                4,756,372,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                5,394,655,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,996,772,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,699,043,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,089,100,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                2,930,833,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,591,865,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,541,485,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,233,318,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | — | 
                                                161.72
                                                
                                             | — | — | — | — | — | 
                                                134.83
                                                
                                             | — | — | — | — | 
                                                139.19
                                                
                                             | 
                                                122.31
                                                
                                             | — | 
                                                110.27
                                                
                                             | 
                                                117.54
                                                
                                             | — | — | — | 
                                                84.28
                                                
                                             | 
                                                78.05
                                                
                                             | 
                                                71.98
                                                
                                             | — | — | 
                                                67.23
                                                
                                             | 
| Basic earnings (loss) per share | — | — | — | 
                                                29.23
                                                
                                             | — | — | — | — | — | — | 
                                                19.46
                                                
                                             | 
                                                15.70
                                                
                                             | 
                                                25.27
                                                
                                             | — | — | 
                                                30.82
                                                
                                             | — | — | 
                                                31.94
                                                
                                             | 
                                                18.69
                                                
                                             | 
                                                20.06
                                                
                                             | — | — | — | 
                                                11.08
                                                
                                             | 
                                                11.88
                                                
                                             | — | 
| Diluted earnings per share | — | — | — | 
                                                29.20
                                                
                                             | — | — | — | — | — | — | 
                                                19.45
                                                
                                             | 
                                                15.68
                                                
                                             | 
                                                25.24
                                                
                                             | — | — | 
                                                30.71
                                                
                                             | — | — | 
                                                31.83
                                                
                                             | 
                                                18.59
                                                
                                             | 
                                                19.95
                                                
                                             | — | — | — | 
                                                10.99
                                                
                                             | 
                                                11.78
                                                
                                             | — | 
| Equity-to-asset ratio | — | — | 
                                                0.499
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                0.569
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.523
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.620
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.610
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.589
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.584
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.612
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.588
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.625
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | — | 
                                                0.194
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                0.151
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.136
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.198
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.327
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.316
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.258
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.258
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.180
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.180
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | — | — | 
                                                14.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                21.4
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                32.7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                20.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                35.5
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                34.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                31.1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                29.0
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                55.5
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                51.7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | — | — | 
                                                603,226,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                457,634,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                846,961,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                505,343,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                291,147,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | — | — | 
                                                -865,662,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                -859,530,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -639,671,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -104,258,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -93,022,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | — | — | 
                                                439,156,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                625,080,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -29,438,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -235,613,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -4,956,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | — | 
                                                1,916,852,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
                                                1,740,719,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,515,447,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,336,533,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,170,437,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Number of employees | 
                                                74
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                743
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                817
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                15
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                612
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                116
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                15
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                89
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                74
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                801
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                96
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                520
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                640
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                546
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                450
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                489
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                390
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                110
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                116
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                84
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                26
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                131
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                123
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                149
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                165
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                138
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                157
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                136
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |