Key Financial Data Of Group
| Concept | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 2023-04-01 to 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 2022-04-01 to 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | 2022-04-01 to 2023-03-31 | 2021-04-01 to 2022-03-31 | 2021-04-01 to 2022-03-31 | As at 2022-03-31 | As at 2022-03-31 | As at 2021-03-31 | 2020-04-01 to 2021-03-31 | 2020-04-01 to 2021-03-31 | As at 2021-03-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Key financial data of group | ||||||||||||||||||||||||
| Business results of group | ||||||||||||||||||||||||
| Net sales | — | — | — | — | — | 
                                                91,947,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                89,601,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                89,809,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                91,676,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                77,458,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                80,171,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                67,297,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                68,820,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                68,968,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                70,435,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | — | — | — | — | 
                                                7,582,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                7,391,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,707,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,896,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,059,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,127,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,433,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,596,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                2,477,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,486,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | — | — | — | — | — | 
                                                6,229,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,712,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2,480,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,860,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,821,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Comprehensive income | — | — | — | — | — | 
                                                4,904,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                4,564,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1,754,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,291,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                3,733,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | — | — | — | 
                                                42,027,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                41,303,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                38,756,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                38,068,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                35,035,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                35,380,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                34,360,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                33,860,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                33,666,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                33,299,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | — | — | — | 
                                                80,861,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                78,845,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                84,012,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                82,209,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                77,063,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                78,941,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                72,081,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                70,650,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                71,500,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                70,305,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | — | — | — | 
                                                1,631.80
                                                
                                             | — | 
                                                1,603.67
                                                
                                             | — | — | — | 
                                                1,506.49
                                                
                                             | 
                                                1,479.74
                                                
                                             | — | 
                                                1,363.27
                                                
                                             | 
                                                1,376.70
                                                
                                             | — | — | — | 
                                                1,339.15
                                                
                                             | 
                                                1,319.65
                                                
                                             | 
                                                1,314.95
                                                
                                             | — | — | 
                                                1,300.63
                                                
                                             | 
| Basic earnings (loss) per share | — | — | — | — | — | 
                                                241.95
                                                
                                             | — | 
                                                237.04
                                                
                                             | 
                                                139.77
                                                
                                             | 
                                                144.35
                                                
                                             | — | — | 
                                                98.40
                                                
                                             | — | — | 
                                                96.58
                                                
                                             | 
                                                68.64
                                                
                                             | 
                                                72.56
                                                
                                             | — | — | — | 
                                                71.38
                                                
                                             | 
                                                71.19
                                                
                                             | — | 
| Diluted earnings per share | — | — | — | — | — |  | — |  |  |  | — | — |  | — | — |  |  |  | — | — | — |  |  | — | 
| Equity-to-asset ratio | — | — | — | — | 
                                                0.520
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.524
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.461
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.463
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.455
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.448
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.477
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.479
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.471
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.474
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | — | — | — | 
                                                0.154
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.154
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.098
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.100
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.073
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.071
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.052
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.055
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.057
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.057
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | — | — | — | — | 
                                                8.0
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                8.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                12.0
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                11.6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                11.1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                11.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                11.7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                11.0
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                10.7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                10.7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | — | — | — | — | 
                                                1,276,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                2,010,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -34,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,648,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -1,459,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | — | — | — | — | 
                                                612,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -304,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -481,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                89,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -170,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | — | — | — | — | 
                                                -1,528,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -1,293,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -1,349,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,297,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -1,453,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | — | — | — | 
                                                18,389,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                17,979,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                17,540,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                19,390,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                15,919,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Number of employees | 
                                                1,010
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                82
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                955
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                82
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,092
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1,037
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                987
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                935
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                946
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                993
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                987
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                939
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                997
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                952
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | — | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                95
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                95
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                94
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                94
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                96
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                95
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                101
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                100
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |