Key Financial Data Of Reporting Company
| 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 reporting company | ||||||
| Business results of reporting company | ||||||
| Net sales | — | 
                                                2,493,628,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,594,555,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,927,829,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | 
                                                -32,119,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                326,469,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -4,032,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                2,362,305,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,432,504,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,187,243,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                6,145,933,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,602,466,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,139,478,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | — | 
                                                -15.63
                                                
                                             | 
                                                46.26
                                                
                                             | — | — | 
                                                -5.59
                                                
                                             | 
| Diluted earnings per share | — |  | 
                                                45.59
                                                
                                             | — | — |  | 
| Equity-to-asset ratio | 
                                                0.362
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.416
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.339
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                -266,157,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                479,607,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -671,201,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | 
                                                -50,322,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -139,884,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -32,872,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | 
                                                626,119,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -314,448,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                702,023,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                984,195,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                675,550,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                647,018,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — |