Key Financial Data Of Group
| Concept | As at 2024-12-31 | 2024-07-01 to 2024-12-31 | 2023-07-01 to 2024-06-30 | As at 2024-06-30 | As at 2023-12-31 | 2023-07-01 to 2023-12-31 | 
|---|---|---|---|---|---|---|
| Key financial data of group | ||||||
| Business results of group | ||||||
| Net sales | — | 
                                                12,259,451,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                22,134,145,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                11,382,942,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | 
                                                3,065,617,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,368,056,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,440,109,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Profit (loss) attributable to owners of parent | — | 
                                                2,049,328,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,946,337,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,563,306,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Comprehensive income | — | 
                                                2,053,876,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,970,659,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,537,530,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                26,558,008,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                25,051,674,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                21,985,595,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                33,575,928,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                32,004,016,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                29,642,592,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | — | 
                                                48.66
                                                
                                             | 
                                                74.14
                                                
                                             | — | — | 
                                                39.46
                                                
                                             | 
| Diluted earnings per share | — |  |  | — | — |  | 
| Equity-to-asset ratio | 
                                                0.7910
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.7828
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.7417
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                1,008,316,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,830,664,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,540,318,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | 
                                                -3,705,028,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,471,124,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -644,320,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | 
                                                -737,872,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                795,246,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -639,109,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                9,751,143,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                13,195,373,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,291,783,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — |