Key Financial Data Of Reporting Company
| Concept | As at 2023-08-31 | 2023-06-01 to 2023-08-31 | As at 2023-05-31 | 2022-06-01 to 2023-05-31 | 2022-06-01 to 2022-08-31 | As at 2022-08-31 | 
|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||
| Business results of reporting company | ||||||
| Net sales | — | 
                                                1,516,540,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,291,379,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,526,467,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | 
                                                44,705,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                350,890,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                118,448,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) | — | 
                                                22,666,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                256,302,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                86,354,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Equity in earnings (losses) of affiliates if equity method is applied | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Share capital | 
                                                143,172,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                143,172,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                143,172,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total number of issued shares | 
                                                4,095,500
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | 
                                                4,095,500
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | 
                                                4,095,500
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
| Net assets | 
                                                1,886,101,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,915,229,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,698,760,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | 
                                                4,835,495,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,948,311,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,754,014,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Dividend paid per share | — |  | — | 
                                                19.00
                                                
                                             |  | — | 
| Basic earnings (loss) per share | — | 
                                                5.76
                                                
                                             | — | 
                                                67.94
                                                
                                             | 
                                                23.13
                                                
                                             | — | 
| Diluted earnings per share | — | 
                                                5.64
                                                
                                             | — | 
                                                64.12
                                                
                                             | 
                                                22.75
                                                
                                             | — | 
| Equity-to-asset ratio | 
                                                0.390
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.387
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.357
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |