Key Financial Data Of Group
| Concept | As at 2024-03-31 | 2024-01-01 to 2024-03-31 | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | 2023-01-01 to 2023-03-31 | As at 2023-03-31 | 
|---|---|---|---|---|---|---|
| Key financial data of group | ||||||
| Business results of group | ||||||
| Net sales | — | 
                                                2,161,011,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,025,083,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,653,539,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | 
                                                72,603,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,238,574,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                478,845,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | — | 
                                                13,223,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                780,683,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                260,963,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Comprehensive income | — | 
                                                62,503,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                785,126,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                265,587,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | 
                                                6,405,283,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                6,822,364,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,000,839,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | 
                                                9,976,717,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                10,874,682,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,785,833,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Basic earnings (loss) per share | — | 
                                                1.12
                                                
                                             | 
                                                67.51
                                                
                                             | — | 
                                                22.75
                                                
                                             | — | 
| Diluted earnings per share | — | 
                                                1.11
                                                
                                             | 
                                                66.47
                                                
                                             | — | 
                                                22.40
                                                
                                             | — | 
| Equity-to-asset ratio | 
                                                0.331
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.340
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.328
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |