Key Financial Data Of Group
| Concept | As at 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 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 | 2019-04-01 to 2020-03-31 | As at 2020-03-31 | 2019-04-01 to 2020-03-31 | As at 2020-03-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Key financial data of group | |||||||||||||||||||||||||||
| Business results of group | |||||||||||||||||||||||||||
| Net sales | — | — | 
                                                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
                                                    
                                                
                                             | — | 
                                                16,325,908,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                29,087,314,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | — | 
                                                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
                                                    
                                                
                                             | — | 
                                                1,183,565,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,830,691,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | — | — | — | — | — | 
                                                1,591,060,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                1,275,857,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,372,498,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,179,342,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,131,023,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Comprehensive income | — | — | — | — | — | 
                                                1,724,758,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                1,214,393,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,407,945,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,447,706,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,167,444,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | — | — | — | — | — | 
                                                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
                                                    
                                                
                                             | — | 
                                                13,180,812,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                9,583,329,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | — | — | — | — | — | 
                                                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
                                                    
                                                
                                             | — | 
                                                25,040,517,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                18,223,471,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | — | — | — | — | — | 
                                                1,941.07
                                                
                                             | — | 
                                                1,374.00
                                                
                                             | — | — | — | 
                                                1,279.32
                                                
                                             | 
                                                1,797.89
                                                
                                             | — | — | — | 
                                                1,699.36
                                                
                                             | 
                                                1,223.84
                                                
                                             | 
                                                1,574.54
                                                
                                             | — | — | 
                                                1,151.71
                                                
                                             | — | 
                                                1,446.65
                                                
                                             | — | 
                                                1,051.81
                                                
                                             | 
| Basic earnings (loss) per share | — | — | 
                                                128.61
                                                
                                             | — | — | 
                                                173.80
                                                
                                             | — | — | — | — | — | 
                                                96.11
                                                
                                             | — | — | 
                                                139.57
                                                
                                             | 
                                                97.86
                                                
                                             | 
                                                150.35
                                                
                                             | — | — | — | 
                                                102.55
                                                
                                             | 
                                                129.34
                                                
                                             | — | 
                                                88.43
                                                
                                             | — | 
                                                124.17
                                                
                                             | — | 
| Diluted earnings per share | — | — |  | — | — |  | — | — | — | — | — |  | — | — |  |  |  | — | — | — |  |  | — |  | — |  | — | 
| Equity-to-asset ratio | — | — | — | — | — | — | 
                                                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
                                                    
                                                
                                             | — | 
                                                0.526
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.526
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | 
                                                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
                                                    
                                                
                                             | — | 
                                                0.0867
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.0888
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | — | 
                                                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
                                                    
                                                
                                             | — | 
                                                7.25
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                5.16
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | — | — | — | — | 
                                                1,976,102,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                1,321,478,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                965,187,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,579,974,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,659,456,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | — | — | — | — | 
                                                -1,091,914,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                -802,870,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,098,549,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -735,668,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -303,665,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | — | — | — | — | 
                                                -486,814,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                -446,033,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -263,168,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -197,726,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -235,742,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | — | — | — | — | — | 
                                                8,433,138,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                8,022,014,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                7,911,746,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,278,788,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                7,642,610,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Number of employees | 
                                                33
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                33
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                95
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                98
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                594
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                216
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                249
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                152
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                216
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                251
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                584
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                561
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                251
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                566
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                251
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                565
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                252
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | — | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                22
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                23
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                25
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |