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 | 2024-04-01 to 2025-03-31 | As at 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 | — | — | 
                                                32,646,679,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                18,352,492,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                18,652,571,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                32,273,496,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                14,194,024,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                27,164,885,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                15,839,019,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                27,708,983,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                14,737,246,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                26,250,632,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | — | 
                                                3,123,865,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2,301,253,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,582,212,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,346,984,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,159,491,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,898,253,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,190,743,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,047,161,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,320,819,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,860,709,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | — | — | 
                                                1,787,461,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1,591,060,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1,275,857,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,372,498,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,179,342,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Comprehensive income | — | — | 
                                                1,785,559,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1,724,758,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1,214,393,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,407,945,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,447,706,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                18,984,443,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                13,640,240,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                17,778,346,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,584,521,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                11,700,820,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                16,443,759,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                15,519,165,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,176,556,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                14,363,491,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                10,506,275,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | 
                                                30,294,025,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                21,049,408,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                33,218,092,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,658,149,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                20,284,197,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                29,115,187,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                27,190,870,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                19,830,054,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                26,049,081,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                18,724,684,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | 
                                                2,069.88
                                                
                                             | — | — | 
                                                1,487.20
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                1,941.07
                                                
                                             | 
                                                1,374.00
                                                
                                             | — | 
                                                1,279.32
                                                
                                             | 
                                                1,797.89
                                                
                                             | — | — | — | 
                                                1,699.36
                                                
                                             | 
                                                1,223.84
                                                
                                             | 
                                                1,574.54
                                                
                                             | — | — | 
                                                1,151.71
                                                
                                             | 
| Basic earnings (loss) per share | — | — | 
                                                194.98
                                                
                                             | — | — | — | — | — | 
                                                183.52
                                                
                                             | — | — | 
                                                128.61
                                                
                                             | 
                                                173.80
                                                
                                             | — | — | 
                                                96.11
                                                
                                             | — | — | 
                                                139.57
                                                
                                             | 
                                                97.86
                                                
                                             | 
                                                150.35
                                                
                                             | — | — | — | 
                                                102.55
                                                
                                             | 
                                                129.34
                                                
                                             | — | 
| Diluted earnings per share | — | — |  | — | — | — | — | — |  | — | — |  |  | — | — |  | — | — |  |  |  | — | — | — |  |  | — | 
| Equity-to-asset ratio | — | 
                                                0.627
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.648
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                0.535
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.510
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.577
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.565
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.571
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.564
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.551
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.561
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | 
                                                0.0972
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                0.1283
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.0970
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.0930
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.0768
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.0798
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.0824
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.0919
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.0931
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.0856
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | — | 
                                                7.67
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                8.15
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                11.76
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                8.71
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                9.36
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                6.45
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                9.04
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5.89
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                9.64
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                7.65
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                1,128,664,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1,976,102,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1,321,478,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                965,187,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,579,974,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -839,994,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                -1,091,914,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -802,870,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,098,549,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -735,668,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | — | 
                                                -1,105,701,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                -486,814,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -446,033,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -263,168,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -197,726,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                7,663,185,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                8,433,138,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                8,022,014,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                7,911,746,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,278,788,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Number of employees | 
                                                39
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                610
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                213
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                252
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                155
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                103
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                39
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                100
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                213
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                594
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                249
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                251
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                584
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                561
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                251
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                566
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                251
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                22
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                23
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |