Key Financial Data Of Reporting Company
| Concept | 2024-01-01 to 2024-06-30 | As at 2024-06-30 | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | 2023-01-01 to 2023-06-30 | As at 2023-06-30 | 
|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||
| Business results of reporting company | ||||||
| Net sales | 
                                                2,771,485,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,219,251,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,990,020,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | 
                                                -88,785,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                357,368,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -56,535,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                1,024,024,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,745,323,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,353,145,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | 
                                                4,208,792,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,995,486,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,508,614,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Basic earnings (loss) per share | 
                                                -15.74
                                                
                                             | — | 
                                                -20.43
                                                
                                             | — | 
                                                -8.78
                                                
                                             | — | 
| Diluted earnings per share |  | — |  | — |  | — | 
| Equity-to-asset ratio | — | 
                                                0.188
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.190
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.236
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Net cash provided by (used in) operating activities | 
                                                -4,833,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -45,203,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                11,831,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | 
                                                80,549,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                193,138,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -91,573,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | 
                                                -547,386,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                355,912,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                306,405,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                967,027,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,436,023,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,159,894,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |