Consolidated Statement Of Changes In Equity
| Concept | 
                                    
                                        As at 2024-06-30  | 
                            
                                
                                    
                                        2024-01-01 to 2024-06-30  | 
                            
                                
                                    
                                        As at 2023-12-31  | 
                            
                                
                                    
                                        2023-01-01 to 2023-06-30  | 
                            
                        
|---|---|---|---|---|
| Consolidated statement of changes in equity | ||||
| Statement of changes in equity | ||||
| Net assets | 
                                        
                                             
                                                51,928,096,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | 
                                        
                                             
                                                50,442,771,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | 
| Changes during period | ||||
| Profit (loss) attributable to owners of parent | — | 
                                        
                                             
                                                1,539,852,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | 
                                        
                                             
                                                1,482,220,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     |