Key Financial Data Of Group
| 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 group | ||||||
| Business results of group | ||||||
| Net sales | 
                                                3,962,616,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                7,100,488,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,380,727,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | 
                                                485,581,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,459,812,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                595,179,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | 
                                                315,095,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                970,017,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                392,763,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Comprehensive income | 
                                                371,919,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,065,673,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                445,430,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                6,866,082,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,320,280,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,582,548,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | 
                                                16,334,134,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                17,234,455,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                15,156,594,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Basic earnings (loss) per share | 
                                                11.76
                                                
                                             | — | 
                                                37.01
                                                
                                             | — | 
                                                14.95
                                                
                                             | — | 
| Diluted earnings per share | 
                                                11.75
                                                
                                             | — | 
                                                36.99
                                                
                                             | — | 
                                                14.94
                                                
                                             | — | 
| Equity-to-asset ratio | — | 
                                                0.419
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.365
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.367
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Net cash provided by (used in) operating activities | 
                                                -523,941,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,346,221,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -718,475,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | 
                                                -491,191,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -179,434,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -307,406,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | 
                                                -267,728,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -894,165,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -788,423,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                3,817,114,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,099,976,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,013,048,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |