Key Financial Data Of Group
| Concept | As at 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | 2023-04-01 to 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 2022-04-01 to 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | 2022-04-01 to 2023-03-31 | 2021-04-01 to 2022-03-31 | 2021-04-01 to 2022-03-31 | As at 2022-03-31 | As at 2022-03-31 | As at 2021-03-31 | 2020-04-01 to 2021-03-31 | 2020-04-01 to 2021-03-31 | As at 2021-03-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Key financial data of group | |||||||||||||||||||||||||||||
| Business results of group | |||||||||||||||||||||||||||||
| Net sales | — | — | 
                                                10,837,189,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                9,572,658,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,435,466,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,045,586,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                8,051,251,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                37,449,092,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,046,965,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                37,205,435,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                5,484,558,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                26,662,815,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | — | 
                                                709,844,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                424,496,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                433,911,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -4,114,510,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,415,618,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                14,174,666,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,579,594,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,673,717,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -52,011,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                881,396,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | — | — | 
                                                17,228,604,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                -3,777,621,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                6,878,387,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,818,774,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                47,377,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Comprehensive income | — | — | 
                                                12,310,098,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                3,531,951,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                13,510,337,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,375,523,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -435,214,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                47,608,278,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                25,266,925,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
                                                37,259,391,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                37,299,093,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                31,876,890,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                35,013,806,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                27,040,281,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                32,080,501,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                20,820,746,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,655,941,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | 
                                                53,127,459,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                30,150,368,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
                                                46,838,448,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                45,640,321,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                36,848,260,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                41,767,380,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                82,088,168,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                47,076,287,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                49,785,150,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                13,465,520,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | 
                                                2,135.24
                                                
                                             | — | — | 
                                                1,131.91
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
                                                1,670.86
                                                
                                             | 
                                                1,672.64
                                                
                                             | — | 
                                                1,403.78
                                                
                                             | 
                                                1,542.39
                                                
                                             | — | — | — | 
                                                1,018.23
                                                
                                             | 
                                                1,337.97
                                                
                                             | 
                                                601.92
                                                
                                             | — | — | 
                                                234.60
                                                
                                             | 
| Basic earnings (loss) per share | — | — | 
                                                774.02
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                -37.54
                                                
                                             | — | 
                                                19.75
                                                
                                             | 
                                                -169.82
                                                
                                             | — | — | 
                                                136.78
                                                
                                             | — | — | 
                                                292.82
                                                
                                             | 
                                                1,002.69
                                                
                                             | 
                                                117.77
                                                
                                             | — | — | — | 
                                                -3.66
                                                
                                             | 
                                                2.08
                                                
                                             | — | 
| Diluted earnings per share | — | — | 
                                                772.65
                                                
                                             | — | — | — | — | — | — | — | — |  | — | 
                                                19.73
                                                
                                             |  | — | — | 
                                                136.55
                                                
                                             | — | — | 
                                                278.46
                                                
                                             | 
                                                1,000.79
                                                
                                             | 
                                                108.47
                                                
                                             | — | — | — |  | 
                                                1.98
                                                
                                             | — | 
| Equity-to-asset ratio | — | 
                                                0.895
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.836
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
                                                0.793
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.815
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.862
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.836
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.297
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.680
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.289
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.417
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | 
                                                0.407
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                -0.027
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.013
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                -0.102
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.101
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.232
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1.275
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.145
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                -0.018
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.003
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | — | 
                                                9.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                172.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                14.1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                6.6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1.9
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                16.5
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,766.8
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                -1,668,247,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                2,509,798,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -13,518,612,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,632,940,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                6,110,885,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | — | 
                                                2,952,409,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                -3,562,671,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -25,131,298,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,020,857,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -910,832,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | — | 
                                                -829,425,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                -385,206,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                25,574,225,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -3,036,636,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                3,598,193,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                1,986,385,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                1,519,890,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                2,934,094,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                27,438,438,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                21,113,250,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Number of employees | 
                                                54
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                304
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                120
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                220
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                155
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                9
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                37
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                54
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                86
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                9
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                301
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                209
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                217
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                302
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1,171
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                224
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,038
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                240
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                11
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                69
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                11
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                26
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                54
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                4
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                11
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                4
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                93
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                22
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                16
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                89
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                102
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                13
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                88
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                9
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |