Key Financial Data Of Group
| Concept | As at 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 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 | — | — | 
                                                54,827,987,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                48,890,616,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                48,379,011,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                51,900,205,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                44,249,112,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                49,000,185,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                35,539,521,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                36,650,986,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                29,975,098,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                32,929,473,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | — | 
                                                6,888,498,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,155,993,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,200,895,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,323,852,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,712,514,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,380,011,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,090,119,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,055,242,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                2,110,551,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,920,909,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | — | — | 
                                                4,812,530,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                5,098,832,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                3,752,085,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,748,804,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,944,387,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Comprehensive income | — | — | 
                                                5,617,437,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                5,736,444,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                4,102,709,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,516,144,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                2,370,952,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                41,040,241,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                27,542,870,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                37,575,881,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                26,554,331,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                24,824,260,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                34,194,191,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                31,303,436,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                23,252,109,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                29,962,424,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                22,685,235,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | 
                                                64,204,971,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                49,390,726,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                56,347,242,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                45,111,219,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                42,907,327,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                53,237,235,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                45,827,302,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                37,611,131,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                43,379,486,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                35,556,348,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | 
                                                1,486.10
                                                
                                             | — | 
                                                1,001.58
                                                
                                             | — | — | — | — | 
                                                1,347.30
                                                
                                             | 
                                                956.33
                                                
                                             | — | 
                                                880.05
                                                
                                             | 
                                                1,206.75
                                                
                                             | — | — | — | 
                                                1,097.97
                                                
                                             | 
                                                819.28
                                                
                                             | 
                                                1,036.37
                                                
                                             | — | — | 
                                                788.02
                                                
                                             | 
| Basic earnings (loss) per share | — | — | 
                                                173.80
                                                
                                             | — | — | 
                                                104.43
                                                
                                             | 
                                                129.95
                                                
                                             | 
                                                182.16
                                                
                                             | — | — | 
                                                93.48
                                                
                                             | — | — | 
                                                132.47
                                                
                                             | 
                                                74.16
                                                
                                             | 
                                                95.76
                                                
                                             | — | — | — | 
                                                49.23
                                                
                                             | 
                                                67.20
                                                
                                             | — | 
| Diluted earnings per share | — | — |  | — | — |  |  |  | — | — |  | — | — |  |  |  | — | — | — |  |  | — | 
| Equity-to-asset ratio | — | 
                                                0.637
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.558
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.664
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.589
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.579
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.639
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.680
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.618
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.688
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.638
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | 
                                                0.123
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.107
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.142
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.143
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.110
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.115
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.093
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.090
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.064
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.066
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | — | 
                                                10.9
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                18.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                15.5
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                11.1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                15.0
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                10.6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                11.8
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                9.1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                22.0
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                16.1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                3,910,247,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                3,970,011,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2,869,069,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,276,164,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                4,099,008,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -1,084,444,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -2,757,913,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -867,940,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -615,898,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -2,017,645,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | — | 
                                                4,371,583,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -2,489,006,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -158,974,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -2,222,028,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -1,731,115,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                18,915,664,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                11,324,435,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                12,509,105,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                10,613,775,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                11,049,865,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Number of employees | 
                                                517
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                807
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                517
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                807
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                761
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                484
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                469
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                727
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                707
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                455
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                709
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                461
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                80
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                123
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                80
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                123
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                128
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                81
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                76
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                122
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                124
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                79
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                122
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                71
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |