Key Financial Data Of Reporting Company
| Concept | 2024-01-01 to 2024-03-31 | As at 2024-03-31 | 2023-10-01 to 2024-03-31 | 2022-10-01 to 2023-09-30 | As at 2023-09-30 | As at 2023-03-31 | 2023-01-01 to 2023-03-31 | 2022-10-01 to 2023-03-31 | 
|---|---|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||||
| Business results of reporting company | ||||||||
| Net sales | — | — | 
                                                804,896,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,155,988,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                616,712,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | — | 
                                                29,872,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                76,134,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                55,099,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Profit (loss) | — | — | — | 
                                                53,394,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                35,698,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | — | 
                                                798,188,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                688,574,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                670,265,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Total assets | — | 
                                                1,335,261,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                932,040,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                943,309,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Basic earnings (loss) per share | 
                                                0.85
                                                
                                             | — | 
                                                18.51
                                                
                                             | 
                                                48.66
                                                
                                             | — | — | 
                                                15.85
                                                
                                             | 
                                                32.73
                                                
                                             | 
| Diluted earnings per share | — | — | 
                                                18.24
                                                
                                             | 
                                                47.79
                                                
                                             | — | — | — | 
                                                32.11
                                                
                                             | 
| Equity-to-asset ratio | — | 
                                                0.490
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.739
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.711
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                139,916,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                43,591,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                75,137,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -134,417,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -68,887,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -8,200,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | — | 
                                                -66,700,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                192,647,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                187,530,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | — | 
                                                460,066,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                521,268,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                608,384,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — |