Key Financial Data Of Reporting Company
| Concept | As at 2023-09-30 | 2023-07-01 to 2023-09-30 | 2023-04-01 to 2023-09-30 | As at 2023-03-31 | 2022-04-01 to 2023-03-31 | As at 2022-09-30 | 2022-07-01 to 2022-09-30 | 2022-04-01 to 2022-09-30 | 
|---|---|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||||
| Business results of reporting company | ||||||||
| Net sales | — | — | 
                                                19,200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                42,240,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                21,097,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | — | 
                                                3,095,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,785,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,508,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                50,916,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                47,307,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                45,954,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Total assets | 
                                                58,226,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                54,599,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                52,657,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Basic earnings (loss) per share | — | 
                                                120.39
                                                
                                             | 
                                                203.81
                                                
                                             | — | 
                                                523.94
                                                
                                             | — | 
                                                29.45
                                                
                                             | 
                                                199.84
                                                
                                             | 
| Diluted earnings per share | — | — | 
                                                200.89
                                                
                                             | — | 
                                                523.49
                                                
                                             | — | — |  | 
| Equity-to-asset ratio | 
                                                0.861
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.853
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.860
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                4,920,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,761,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,934,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -2,049,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -2,581,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -765,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | — | 
                                                -483,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -765,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -379,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                23,861,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                20,753,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                18,877,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — |