Key Financial Data Of Reporting Company
| Concept | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | 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 | — | — | — | — | — | — | 
                                                25,162,448,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                15,389,990,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                14,217,920,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                23,739,835,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                12,946,199,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                15,997,838,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,070,865,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                14,340,774,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,710,493,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,427,816,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | — | — | — | — | — | 
                                                494,535,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                694,066,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                597,060,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                82,483,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                596,339,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                567,920,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                577,358,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,135,706,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                468,909,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                713,942,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) | — | — | — | — | — | — | — | — | — | 
                                                110,504,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -501,342,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                323,447,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                364,058,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                325,600,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Share capital | — | — | — | — | — | — | — | 
                                                1,112,363,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1,112,183,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,109,972,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1,101,531,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,094,214,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total number of issued shares | — | — | — | — | — | — | — | 
                                                10,330,469
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | — | 
                                                10,325,669
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | 
                                                10,604,880
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | — | 
                                                10,564,840
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | 
                                                10,513,440
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
| Net assets | — | — | — | — | — | 
                                                2,871,147,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,994,347,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                3,070,641,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,985,062,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,591,083,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,687,486,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                4,470,860,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,604,293,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,830,496,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,303,713,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | — | — | — | — | 
                                                7,374,904,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,396,858,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                7,174,136,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,225,276,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,671,447,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,999,379,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                5,874,294,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,854,614,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,486,303,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,489,511,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | — | — | — | — | 
                                                267.71
                                                
                                             | — | 
                                                282.43
                                                
                                             | — | — | — | — | 
                                                272.09
                                                
                                             | 
                                                282.43
                                                
                                             | — | 
                                                341.64
                                                
                                             | 
                                                416.94
                                                
                                             | — | — | — | 
                                                422.26
                                                
                                             | 
                                                339.92
                                                
                                             | 
                                                365.74
                                                
                                             | — | — | 
                                                315.44
                                                
                                             | 
| Dividend paid per share | — | — | — | — | — | — | — | — | — | 
                                                10.00
                                                
                                             | 
                                                10.00
                                                
                                             | — | — | — | 
                                                10.00
                                                
                                             | — | — | — | 
                                                10.00
                                                
                                             | — | — | — | — | 
                                                10.00
                                                
                                             | — | — | 
| Interim dividend paid per share | — | — | — | — | — | — | — | — | — |  |  | — | — | — |  | — | — | — |  | — | — | — | — |  | — | — | 
| Basic earnings (loss) per share | — | — | — | — | — | — | 
                                                4.82
                                                
                                             | — | — | 
                                                10.70
                                                
                                             | 
                                                -48.57
                                                
                                             | 
                                                -142.75
                                                
                                             | — | — | 
                                                30.73
                                                
                                             | — | — | 
                                                23.20
                                                
                                             | 
                                                34.68
                                                
                                             | 
                                                67.18
                                                
                                             | — | — | — | 
                                                31.18
                                                
                                             | 
                                                43.83
                                                
                                             | — | 
| Diluted earnings per share | — | — | — | — | — | — | 
                                                4.82
                                                
                                             | — | — | 
                                                10.70
                                                
                                             |  |  | — | — | 
                                                30.46
                                                
                                             | — | — | 
                                                22.99
                                                
                                             | 
                                                34.16
                                                
                                             | 
                                                66.17
                                                
                                             | — | — | — | 
                                                30.63
                                                
                                             | 
                                                43.06
                                                
                                             | — | 
| Equity-to-asset ratio | — | — | — | — | — | 
                                                0.375
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.456
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.392
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.468
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.528
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.477
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.757
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.737
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.591
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.736
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | — | — | — | — | 
                                                0.018
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.038
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                -0.156
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                -0.415
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.091
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.056
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.106
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.170
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.104
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.127
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | — | — | — | — | — | 
                                                82.9
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                37.4
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                31.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                41.4
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                46.4
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                24.0
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                41.6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                29.6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Payout ratio | — | — | — | — | — | — | — | — | — | 
                                                0.934
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.325
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.288
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.321
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | — | — | — | — | — | 
                                                46,813,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -3,827,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                688,038,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                369,207,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                661,718,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | — | — | — | — | — | 
                                                -418,942,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                317,149,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -1,560,893,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -68,653,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -48,908,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | — | — | — | — | — | 
                                                226,952,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -330,211,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1,274,450,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -91,339,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -22,588,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | — | — | — | — | 
                                                3,606,612,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                3,749,726,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,755,033,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,357,198,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,149,695,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Number of employees | 
                                                58
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                184
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                23
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                146
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                26
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                291
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                172
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                26
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                268
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                167
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                128
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                473
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                384
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                124
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                357
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                106
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Total shareholder return | — | — | — | — | — | — | — | 
                                                0.414
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                0.516
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.938
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1.282
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1.698
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Total return on share price index | — | — | — | — | — | — | — | 
                                                1.895
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1.973
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1.428
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1.387
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1.393
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |