Key Financial Data Of Group
| Concept | As at 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 2022-04-01 to 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | 2022-04-01 to 2023-03-31 | 2021-04-01 to 2022-03-31 | 2021-04-01 to 2022-03-31 | As at 2022-03-31 | As at 2022-03-31 | As at 2021-03-31 | 2020-04-01 to 2021-03-31 | 2020-04-01 to 2021-03-31 | As at 2021-03-31 | 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 | — | — | 
                                                58,324,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                72,196,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                56,369,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                70,437,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                52,979,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                67,206,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                52,249,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                64,881,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                62,499,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                74,814,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | — | 
                                                1,656,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,716,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,115,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,102,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,297,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,889,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -1,705,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,472,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,539,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,529,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | — | — | — | 
                                                1,396,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -3,041,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                736,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -1,149,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -267,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Comprehensive income | — | — | — | 
                                                1,401,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -3,039,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                750,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -1,114,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -270,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | — | — | — | 
                                                10,108,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,711,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,339,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,696,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                11,727,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,029,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,967,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                10,759,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                12,082,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                12,081,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | — | — | — | 
                                                30,191,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                28,255,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                26,950,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                28,938,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                31,648,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                29,262,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                32,007,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                30,072,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                28,926,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                27,097,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | — | — | — | 
                                                203.30
                                                
                                             | 
                                                196.82
                                                
                                             | — | 
                                                169.03
                                                
                                             | 
                                                174.79
                                                
                                             | — | — | — | 
                                                235.80
                                                
                                             | 
                                                223.56
                                                
                                             | 
                                                221.57
                                                
                                             | — | — | 
                                                218.11
                                                
                                             | — | 
                                                244.83
                                                
                                             | — | 
                                                244.90
                                                
                                             | 
| Basic earnings (loss) per share | — | — | 
                                                27.64
                                                
                                             | 
                                                28.29
                                                
                                             | — | — | 
                                                -55.18
                                                
                                             | — | — | 
                                                -61.65
                                                
                                             | 
                                                6.12
                                                
                                             | 
                                                14.92
                                                
                                             | — | — | — | 
                                                -26.79
                                                
                                             | 
                                                -23.31
                                                
                                             | — | 
                                                -4.27
                                                
                                             | — | 
                                                -5.45
                                                
                                             | — | 
| Diluted earnings per share | — | — |  |  | — | — |  | — | — |  |  |  | — | — | — |  |  | — |  | — |  | — | 
| Equity-to-asset ratio | — | — | — | — | 
                                                0.332
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.344
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.309
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.298
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.368
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.377
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.341
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.358
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.418
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.446
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | 
                                                0.151
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.150
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                -0.281
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                -0.300
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.028
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.065
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                -0.116
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                -0.100
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                -0.017
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                -0.022
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | — | 
                                                58.61
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                57.26
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                221.08
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                90.68
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | — | — | 
                                                3,554,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2,522,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,577,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -538,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,748,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | — | — | 
                                                -2,490,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -1,146,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                306,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -604,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -2,124,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | — | — | 
                                                -644,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -3,265,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,400,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                3,127,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -765,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | — | — | — | 
                                                7,937,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                7,518,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                9,407,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                7,924,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                5,941,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Number of employees | 
                                                123
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                661
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                784
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                661
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                674
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                798
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                790
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                675
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                819
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                706
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                816
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                703
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                578
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5,392
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                5,970
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5,392
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                6,031
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                6,612
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                6,938
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                6,339
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                6,874
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                6,272
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                7,608
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                6,996
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |