Key Financial Data Of Group
| Concept | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 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 | 
                                                23,700,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                37,335,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                30,053,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                43,146,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                39,366,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                51,418,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                48,615,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                55,186,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                47,931,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                54,322,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | 
                                                2,536,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,112,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                2,341,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,700,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,447,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,868,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                7,317,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,836,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,654,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,156,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | — | — | — | 
                                                778,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                260,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,198,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                3,513,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,251,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Comprehensive income | — | — | — | 
                                                1,254,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                479,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,786,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                5,022,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,882,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | — | — | — | 
                                                34,639,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                29,104,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                32,842,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                33,884,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                34,540,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                32,980,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                32,915,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                30,389,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                29,335,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                25,947,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | — | — | — | 
                                                75,606,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                61,843,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                63,794,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                71,387,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                72,601,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                64,886,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                80,591,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                71,398,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                75,119,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                66,977,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | — | — | — | 
                                                3,571.35
                                                
                                             | — | 
                                                3,023.95
                                                
                                             | — | 
                                                3,396.47
                                                
                                             | 
                                                3,475.25
                                                
                                             | — | — | — | 
                                                3,534.40
                                                
                                             | 
                                                3,410.78
                                                
                                             | 
                                                3,233.74
                                                
                                             | — | — | 
                                                3,142.19
                                                
                                             | — | 
                                                2,926.03
                                                
                                             | — | 
                                                2,682.66
                                                
                                             | 
| Basic earnings (loss) per share | 
                                                -326.82
                                                
                                             | — | — | 
                                                80.65
                                                
                                             | — | — | — | 
                                                101.87
                                                
                                             | — | — | 
                                                26.92
                                                
                                             | 
                                                392.14
                                                
                                             | 
                                                434.21
                                                
                                             | — | — | — | 
                                                559.66
                                                
                                             | 
                                                363.41
                                                
                                             | — | 
                                                383.59
                                                
                                             | — | 
                                                336.29
                                                
                                             | — | 
| Diluted earnings per share |  | — | — |  | — | — | — |  | — | — |  |  |  | — | — | — |  |  | — |  | — |  | — | 
| Equity-to-asset ratio | — | — | — | — | 
                                                0.455
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.471
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.515
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.471
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.471
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.508
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.388
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.426
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.377
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.387
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | 
                                                -0.102
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.023
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.030
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.008
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.120
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.128
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.192
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.118
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.149
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.118
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                31.12
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                27.55
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                104.23
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                8.42
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                7.60
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                9.74
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                15.00
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                8.16
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                9.31
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | — | — | 
                                                -4,764,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                -3,284,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,408,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                20,173,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -7,853,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | — | — | 
                                                -440,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                -1,195,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,554,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -1,251,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -3,828,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | — | — | 
                                                1,526,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                2,780,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -5,839,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,972,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                4,074,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | — | — | — | 
                                                22,893,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                26,295,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                27,778,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                33,158,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                11,981,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Number of employees | — | 
                                                111
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                244
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                955
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                844
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                244
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                240
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                947
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                924
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                255
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                825
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                270
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                809
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                272
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | — | 
                                                3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                65
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                109
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                106
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                65
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                91
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                153
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                120
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                79
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                124
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                89
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                160
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                123
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |