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 | — | 
                                                1,674,491,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,683,182,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,382,742,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | 
                                                -421,333,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -318,634,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -92,518,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                4,240,601,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,688,215,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,005,007,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                8,129,119,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                9,509,373,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,846,463,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | — | 
                                                -43.99
                                                
                                             | 
                                                -67.48
                                                
                                             | — | — | 
                                                -11.14
                                                
                                             | 
| Diluted earnings per share | — |  |  | — | — |  | 
| Equity-to-asset ratio | 
                                                0.5217
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.4930
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.5658
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                108,985,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -386,636,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                110,832,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | 
                                                -189,039,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -434,589,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -434,273,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | 
                                                -707,277,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,092,750,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,170,321,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                1,275,954,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,080,097,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,558,051,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — |