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 | 
                                                1,783,273,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,648,872,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,642,597,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | 
                                                92,205,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                298,648,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                47,111,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                3,002,190,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,942,024,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,011,021,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | 
                                                4,346,016,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,305,462,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,102,492,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Basic earnings (loss) per share | 
                                                25.36
                                                
                                             | — | 
                                                32.87
                                                
                                             | — | 
                                                18.83
                                                
                                             | — | 
| Diluted earnings per share |  | — |  | — |  | — | 
| Equity-to-asset ratio | — | 
                                                0.691
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.683
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.734
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Net cash provided by (used in) operating activities | 
                                                45,121,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                63,021,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -423,580,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | 
                                                -120,653,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -61,779,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,152,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | 
                                                -46,448,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                122,983,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                123,050,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                3,343,452,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,403,321,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,980,298,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |