Key Financial Data Of Group
| Concept | 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 | — | 
                                                235,628,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                186,749,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                176,292,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                222,100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                171,582,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                211,285,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                158,233,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                195,700,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                151,398,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                187,509,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | 
                                                18,451,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                13,488,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,207,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                16,780,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                12,548,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                17,328,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                16,531,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                16,703,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                13,873,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                19,381,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | — | 
                                                12,486,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                11,724,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                11,529,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                11,206,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                12,211,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Comprehensive income | — | 
                                                12,812,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                12,485,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                11,558,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                11,118,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                13,021,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | 
                                                154,114,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                120,311,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                145,844,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                115,478,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                113,660,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                140,171,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                132,455,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                108,133,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                124,980,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                98,633,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | 
                                                292,226,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                267,459,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                298,580,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                270,851,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                272,921,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                298,623,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                262,695,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                238,616,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                247,234,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                223,343,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | 
                                                1,897.68
                                                
                                             | — | 
                                                1,488.07
                                                
                                             | — | — | — | 
                                                1,795.71
                                                
                                             | 
                                                1,428.80
                                                
                                             | — | 
                                                1,388.68
                                                
                                             | 
                                                1,703.56
                                                
                                             | — | — | — | 
                                                1,610.11
                                                
                                             | 
                                                1,321.39
                                                
                                             | 
                                                1,520.06
                                                
                                             | — | — | 
                                                1,205.71
                                                
                                             | 
| Basic earnings (loss) per share | — | 
                                                154.46
                                                
                                             | — | 
                                                121.77
                                                
                                             | 
                                                99.87
                                                
                                             | 
                                                143.50
                                                
                                             | — | — | 
                                                116.60
                                                
                                             | — | — | 
                                                140.87
                                                
                                             | 
                                                161.77
                                                
                                             | 
                                                136.96
                                                
                                             | — | — | — | 
                                                114.63
                                                
                                             | 
                                                147.80
                                                
                                             | — | 
| Diluted earnings per share | — |  | — |  |  |  | — | — |  | — | — |  |  |  | — | — | — |  |  | — | 
| Equity-to-asset ratio | 
                                                0.525
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.450
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.486
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.426
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.416
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.467
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.502
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.453
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.503
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.442
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | 
                                                0.084
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.083
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.071
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.082
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.086
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.085
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.128
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.088
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.097
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.100
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | 
                                                18.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                23.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                27.6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                19.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                28.1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                23.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                18.0
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                21.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                39.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                30.5
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                27,919,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                29,176,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                20,071,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                23,148,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                31,814,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -14,929,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -10,711,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -34,306,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -22,866,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -19,131,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | 
                                                -18,070,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -17,013,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                16,745,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,578,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -15,086,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | 
                                                19,020,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                23,707,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                22,255,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                19,745,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                17,884,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Number of employees | 
                                                5,250
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                988
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                5,104
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                984
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                979
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                4,876
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                4,792
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                962
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                4,753
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                944
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                452
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |