Key Financial Data Of Reporting Company
| Concept | As at 2024-09-30 | 2024-04-01 to 2024-09-30 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2023-09-30 | 2023-04-01 to 2023-09-30 | 
|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||
| Business results of reporting company | ||||||
| Net sales | — | 
                                                15,626,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                30,748,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                14,837,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | 
                                                -62,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -219,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                10,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                18,552,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                18,460,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                18,548,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                52,024,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                49,548,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                50,870,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | — | 
                                                -12.26
                                                
                                             | 
                                                -50.14
                                                
                                             | — | — | 
                                                8.72
                                                
                                             | 
| Diluted earnings per share | — |  |  | — | — |  | 
| Equity-to-asset ratio | 
                                                0.357
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.373
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.365
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                702,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                296,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                592,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | 
                                                -88,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,139,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,418,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | 
                                                974,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,447,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,548,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                10,805,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                9,200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,321,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — |