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 | — | 
                                                17,014,250,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                35,664,983,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                16,343,389,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | 
                                                404,856,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,955,910,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                190,381,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                14,739,275,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                14,668,431,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                13,499,286,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                27,455,336,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                27,780,868,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                27,669,688,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | — | 
                                                161.90
                                                
                                             | 
                                                924.18
                                                
                                             | — | — | 
                                                79.70
                                                
                                             | 
| Diluted earnings per share | — |  |  | — | — |  | 
| Equity-to-asset ratio | 
                                                0.532
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.523
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.484
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                725,211,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,588,751,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                631,329,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | 
                                                -305,410,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -583,063,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -509,890,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | 
                                                -533,674,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,491,616,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -275,084,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                1,299,776,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,413,649,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,745,931,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — |