Key Financial Data Of Group
| Concept | 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 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | 2023-04-01 to 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 2022-04-01 to 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | 2022-04-01 to 2023-03-31 | 2021-04-01 to 2022-03-31 | 2021-04-01 to 2022-03-31 | As at 2022-03-31 | As at 2022-03-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Key financial data of group | ||||||||||||||||||||||
| Business results of group | ||||||||||||||||||||||
| Net sales | — | — | — | — | 
                                                64,139,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                62,843,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                60,461,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                56,607,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Operating revenue | — | — | — | — | — | — | — | — | 
                                                4,509,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,716,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,732,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,371,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Ordinary profit (loss) | — | — | — | — | 
                                                5,107,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,191,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,467,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,522,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                603,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,232,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                717,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,880,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Profit (loss) attributable to owners of parent | — | — | — | — | 
                                                5,101,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                7,545,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                4,238,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,290,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Comprehensive income | — | — | — | — | 
                                                5,222,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                8,127,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                5,983,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,982,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net assets | — | — | — | 
                                                69,195,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                44,650,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                61,930,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                42,680,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                40,944,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                54,533,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                48,892,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                40,695,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | — | — | 
                                                100,534,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                48,258,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                90,745,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                43,245,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                41,575,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                87,138,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                83,297,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                41,301,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | — | — | 
                                                2,302.61
                                                
                                             | — | — | 
                                                1,574.11
                                                
                                             | — | — | — | — | — | 
                                                2,186.10
                                                
                                             | 
                                                1,506.47
                                                
                                             | — | 
                                                1,447.55
                                                
                                             | 
                                                1,928.14
                                                
                                             | — | — | — | 
                                                1,734.80
                                                
                                             | 
                                                1,443.94
                                                
                                             | 
| Basic earnings (loss) per share | — | — | — | — | 
                                                179.95
                                                
                                             | — | — | — | 
                                                111.57
                                                
                                             | — | 
                                                87.10
                                                
                                             | 
                                                266.51
                                                
                                             | — | — | 
                                                20.95
                                                
                                             | — | — | 
                                                150.08
                                                
                                             | 
                                                23.79
                                                
                                             | 
                                                151.22
                                                
                                             | — | — | 
| Diluted earnings per share | — | — | — | — |  | — | — | — |  | — |  |  | — | — |  | — | — |  |  |  | — | — | 
| Equity-to-asset ratio | — | — | — | 
                                                0.6496
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.925
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                0.6825
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.987
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.985
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.6258
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.5870
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.985
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | — | — | 
                                                0.0802
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.0724
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.0590
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.1296
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.0145
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.0820
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.0168
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.0877
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Price-earnings ratio | — | — | — | — | 
                                                12.80
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                20.65
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                25.48
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                8.33
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                56.76
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                7.92
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                53.10
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                8.35
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | — | — | — | 
                                                2,485,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                1,486,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                3,351,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,842,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | — | — | — | — | 
                                                -6,124,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                1,706,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -1,126,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,743,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | — | — | — | — | 
                                                -2,956,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                -3,943,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -1,820,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -2,996,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | — | — | 
                                                10,603,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                16,738,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                17,505,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                17,103,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Number of employees | 
                                                857
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                32
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                80
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,632
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                16
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                80
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                92
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                635
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                762
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                75
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                79
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                747
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                777
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                74
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                8
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                137
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                25
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                104
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                127
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                117
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                101
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — |