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 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | 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 | 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 | — | — | 
                                                34,126,910,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                19,861,505,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                19,891,742,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                34,497,568,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                19,087,242,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                34,075,193,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                17,443,508,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                30,720,791,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                15,871,936,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                27,816,453,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | — | 
                                                2,140,270,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1,793,403,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,670,855,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,124,759,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,670,493,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,289,124,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,217,477,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,620,180,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,599,713,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,921,636,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | — | — | 
                                                1,065,449,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                1,258,516,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1,332,846,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,715,583,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,333,897,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Comprehensive income | — | — | 
                                                760,246,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                4,440,893,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2,444,276,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,944,995,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                2,410,910,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                55,375,632,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                46,396,620,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                55,337,828,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                46,530,867,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                43,326,416,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                51,619,238,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                49,659,036,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                42,010,012,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                48,101,422,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                40,703,839,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | 
                                                72,339,141,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                54,599,964,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                73,605,200,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                55,652,173,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                52,048,742,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                70,633,709,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                69,225,291,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                51,641,559,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                65,238,850,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                48,545,150,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | 
                                                1,101.40
                                                
                                             | — | — | — | — | — | — | 
                                                986.37
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                1,084.90
                                                
                                             | 
                                                974.71
                                                
                                             | — | 
                                                895.26
                                                
                                             | 
                                                997.15
                                                
                                             | — | — | — | 
                                                962.55
                                                
                                             | 
                                                868.05
                                                
                                             | 
                                                932.43
                                                
                                             | — | — | 
                                                841.04
                                                
                                             | 
| Basic earnings (loss) per share | — | — | 
                                                22.48
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                22.68
                                                
                                             | — | — | 
                                                21.97
                                                
                                             | 
                                                26.19
                                                
                                             | — | — | 
                                                21.85
                                                
                                             | — | — | 
                                                27.54
                                                
                                             | 
                                                33.00
                                                
                                             | 
                                                35.45
                                                
                                             | — | — | — | 
                                                23.34
                                                
                                             | 
                                                27.56
                                                
                                             | — | 
| Diluted earnings per share | — | — |  | — | — | — | — | — | — | — | — | — |  | — | — |  |  | — | — |  | — | — |  |  |  | — | — | — |  |  | — | 
| Equity-to-asset ratio | — | 
                                                0.716
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                0.850
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                0.704
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.836
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.832
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.683
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.673
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.813
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.692
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.838
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | 
                                                0.021
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                0.023
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.024
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.025
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.025
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.028
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.039
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.037
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.028
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.030
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | — | 
                                                13.8
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                13.7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                15.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                12.7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                13.5
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                10.7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                8.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                7.6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                14.1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                11.9
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                2,366,059,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                3,007,843,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -344,144,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,080,819,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                4,494,818,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -2,106,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                -873,134,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -1,370,526,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -810,332,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -709,592,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | — | 
                                                -1,600,661,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                -2,341,768,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -582,559,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -227,941,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -1,486,522,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                7,330,212,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                8,655,846,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                8,788,194,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                11,094,763,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                10,036,887,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Number of employees | 
                                                156
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                846
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                39
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                507
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                13
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                90
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                90
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                346
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                61
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                156
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                80
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                835
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                329
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                329
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                823
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                821
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                324
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                801
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                307
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |