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 | — | 
                                                3,058,341,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,945,329,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,167,548,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | 
                                                219,560,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                426,132,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                125,422,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Profit (loss) attributable to owners of parent | — | 
                                                143,393,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                299,043,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                92,853,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Comprehensive income | — | 
                                                141,316,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                299,584,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                93,101,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                2,321,987,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,487,830,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,281,411,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                4,181,133,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,765,215,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,670,174,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | — | 
                                                34.17
                                                
                                             | 
                                                69.66
                                                
                                             | — | — | 
                                                21.63
                                                
                                             | 
| Diluted earnings per share | — | 
                                                33.93
                                                
                                             | 
                                                69.09
                                                
                                             | — | — | 
                                                21.45
                                                
                                             | 
| Equity-to-asset ratio | 
                                                0.5553
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.5221
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.4880
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                446,700,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,075,577,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,780,297,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | 
                                                -25,868,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -8,662,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                45,351,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | 
                                                -507,463,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,363,173,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -3,081,137,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                1,644,647,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,732,531,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,762,813,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — |