Key Financial Data Of Group
| Concept | 2024-04-01 to 2024-09-30 | As at 2024-09-30 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | 2023-04-01 to 2023-09-30 | As at 2023-09-30 | 
|---|---|---|---|---|---|---|
| Key financial data of group | ||||||
| Business results of group | ||||||
| Net sales | 
                                                2,568,749,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,888,372,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,742,061,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | 
                                                25,370,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                256,940,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                75,536,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                3,107,272,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,147,880,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,006,867,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | 
                                                5,303,528,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,762,421,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,929,443,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Basic earnings (loss) per share | 
                                                4.12
                                                
                                             | — | — | 
                                                48.82
                                                
                                             | 
                                                12.44
                                                
                                             | — | 
| Diluted earnings per share |  | — | — |  |  | — | 
| Equity-to-asset ratio | — | 
                                                0.586
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.546
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.507
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Net cash provided by (used in) operating activities | 
                                                325,592,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -223,251,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                207,500,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | 
                                                -103,070,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -144,391,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -172,300,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | 
                                                -248,491,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                338,155,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                238,795,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                452,628,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                478,597,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                782,080,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |