Key Financial Data Of Group
| Concept | 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 | 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 | — | — | — | — | — | 
                                                20,533,254,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                19,723,498,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                18,841,240,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                18,849,203,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                19,842,288,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Operating revenue | — | — | — | 
                                                154,778,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                154,778,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                404,778,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                404,760,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                504,752,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Ordinary profit (loss) | — | — | — | 
                                                -61,164,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                666,939,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -27,298,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                386,127,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                211,259,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                603,786,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                226,075,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                756,937,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                345,761,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,196,255,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | — | — | — | — | — | 
                                                469,863,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                204,400,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                347,696,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                412,212,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                673,708,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Comprehensive income | — | — | — | — | — | 
                                                472,360,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                226,090,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                363,031,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                339,350,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                694,215,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | — | — | — | — | — | 
                                                6,653,492,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,487,964,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,610,688,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,315,806,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                6,226,188,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,599,379,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,304,303,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,605,954,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,137,888,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,493,752,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | — | — | — | — | — | 
                                                9,727,185,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,514,559,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,641,783,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,903,483,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                8,645,652,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,658,663,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,065,779,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,654,405,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,877,718,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,679,084,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | — | — | — | — | — | 
                                                491.56
                                                
                                             | — | 
                                                259.05
                                                
                                             | — | — | — | 
                                                268.16
                                                
                                             | 
                                                465.93
                                                
                                             | — | — | — | 
                                                459.57
                                                
                                             | 
                                                267.32
                                                
                                             | 
                                                448.32
                                                
                                             | — | — | 
                                                258.33
                                                
                                             | — | 
                                                433.84
                                                
                                             | — | 
                                                249.19
                                                
                                             | 
| Basic earnings (loss) per share | — | — | — | 
                                                0.89
                                                
                                             | — | 
                                                34.90
                                                
                                             | — | — | — | — | — | 
                                                10.84
                                                
                                             | — | — | 
                                                15.18
                                                
                                             | 
                                                29.14
                                                
                                             | 
                                                25.42
                                                
                                             | — | — | — | 
                                                20.34
                                                
                                             | 
                                                29.41
                                                
                                             | — | 
                                                26.52
                                                
                                             | — | 
                                                48.05
                                                
                                             | — | 
| Diluted earnings per share | — | — | — |  | — |  | — | — | — | — | — |  | — | — |  |  |  | — | — | — |  |  | — |  | — |  | — | 
| Equity-to-asset ratio | — | — | — | — | — | — | 
                                                0.680
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.992
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.992
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.705
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.716
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.984
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.690
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.987
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.685
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.950
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | — | 
                                                0.003
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.073
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                0.041
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.033
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.111
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.056
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.080
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.067
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.110
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.116
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | — | — | 
                                                425.84
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                10.86
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                34.41
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                24.57
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                16.64
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                19.08
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                28.91
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                19.99
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                16.06
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                8.87
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | — | — | — | — | 
                                                713,930,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                662,729,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                196,139,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                227,707,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                579,120,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | — | — | — | — | 
                                                -41,030,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                -21,401,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                55,904,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -960,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                22,385,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | — | — | — | — | 
                                                -140,839,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                -184,589,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -428,938,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -199,259,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -150,464,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | — | — | — | — | — | 
                                                5,570,415,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                5,018,617,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                4,547,931,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,708,552,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                4,675,528,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Number of employees | 
                                                848
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                14
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                516
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1,513
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,513
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                14
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                121
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                14
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                14
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,564
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1,629
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                13
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,583
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                13
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1,487
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                15
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                177
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                743
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                940
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                940
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                19
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                910
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                861
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                852
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                851
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |