Key Financial Data Of Group
| Concept | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 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 | — | — | — | — | — | — | — | 
                                                143,354,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                217,578,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                88,212,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                113,050,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                53,166,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                57,057,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                53,178,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                52,572,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                174,269,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                249,756,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | — | — | — | — | — | — | 
                                                17,269,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                27,225,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                9,156,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -12,064,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -4,485,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -43,861,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -15,827,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -57,320,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,250,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,705,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | — | — | — | — | — | — | — | — | — | 
                                                19,255,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                -3,901,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -25,217,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -36,578,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                5,012,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Comprehensive income | — | — | — | — | — | — | — | — | — | 
                                                28,906,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                -15,056,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -39,533,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -62,212,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                4,119,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | — | — | — | — | — | — | — | — | — | 
                                                166,036,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                151,944,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                143,571,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                140,951,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                156,009,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                139,115,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                195,544,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                142,979,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                201,899,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                100,830,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | — | — | — | — | — | — | — | — | — | 
                                                460,423,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                327,636,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                306,436,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                446,955,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                463,878,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                296,480,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                519,193,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                320,019,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                521,363,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                282,426,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | — | — | — | — | — | — | — | — | — | 
                                                1,805.67
                                                
                                             | — | 
                                                1,631.42
                                                
                                             | — | 
                                                1,541.52
                                                
                                             | 
                                                1,613.62
                                                
                                             | — | — | — | 
                                                1,655.32
                                                
                                             | 
                                                1,493.67
                                                
                                             | 
                                                1,910.83
                                                
                                             | — | — | 
                                                1,535.16
                                                
                                             | — | 
                                                2,001.83
                                                
                                             | — | 
                                                1,241.32
                                                
                                             | 
| Basic earnings (loss) per share | — | — | — | — | — | — | — | 
                                                120.02
                                                
                                             | — | 
                                                206.75
                                                
                                             | — | — | — | 
                                                57.00
                                                
                                             | — | — | 
                                                -41.89
                                                
                                             | 
                                                -47.09
                                                
                                             | 
                                                -270.75
                                                
                                             | — | — | — | 
                                                -145.45
                                                
                                             | 
                                                -445.92
                                                
                                             | — | 
                                                9.34
                                                
                                             | — | 
                                                61.71
                                                
                                             | — | 
| Diluted earnings per share | — | — | — | — | — | — | — |  | — |  | — | — | — |  | — | — |  |  |  | — | — | — |  |  | — | 
                                                9.04
                                                
                                             | — | 
                                                60.20
                                                
                                             | — | 
| Equity-to-asset ratio | — | — | — | — | — | — | — | — | — | — | 
                                                0.3653
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.4638
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.4685
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.3362
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.3324
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.4692
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.3428
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.4468
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.3119
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.3570
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | — | — | — | — | — | 
                                                0.0757
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.1209
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.0376
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.0074
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.0308
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | — | — | — | — | — | — | 
                                                49.41
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                28.68
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                115.79
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                446.78
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                67.65
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | — | — | — | — | — | — | — | — | 
                                                47,761,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                16,326,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -9,305,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -4,387,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                20,222,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | — | — | — | — | — | — | — | — | 
                                                -42,986,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                -10,627,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -4,926,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -25,268,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -57,334,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | — | — | — | — | — | — | — | — | 
                                                -19,649,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                -12,641,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -9,035,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                78,228,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                21,644,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | — | — | — | — | — | — | — | — | — | 
                                                75,395,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                90,241,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                97,128,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                120,355,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                71,795,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Number of employees | 
                                                561
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                981
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                940
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                178
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                70
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                66
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                157
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                136
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                2,660
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,482
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                293
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                272
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,499
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                2,729
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                251
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                3,110
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                264
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                3,095
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                290
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                219
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                152
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                211
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                4
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                586
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                582
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                471
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                399
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                708
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1,389
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |