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 | 
                                                4,559,968,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                10,025,083,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,991,187,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | 
                                                113,701,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,238,574,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                695,101,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | 
                                                13,136,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                780,683,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                406,256,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Comprehensive income | 
                                                128,819,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                785,126,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                411,197,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                6,485,882,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,822,364,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,141,102,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | 
                                                9,567,391,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                10,874,682,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,939,878,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Basic earnings (loss) per share | 
                                                1.11
                                                
                                             | — | 
                                                67.51
                                                
                                             | — | 
                                                35.38
                                                
                                             | — | 
| Diluted earnings per share | 
                                                1.10
                                                
                                             | — | 
                                                66.47
                                                
                                             | — | 
                                                34.87
                                                
                                             | — | 
| Equity-to-asset ratio | — | 
                                                0.354
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.340
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.339
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Net cash provided by (used in) operating activities | 
                                                -2,478,872,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                225,607,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                371,742,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | 
                                                -20,079,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,377,671,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -68,815,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | 
                                                -3,171,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,787,732,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,100,207,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                3,343,175,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,838,745,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,605,814,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |