Shareholdings
| Concept | As at 2024-12-31 | As at 2024-12-31 | As at 2024-12-31 | As at 2024-12-31 | As at 2024-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | 
|---|---|---|---|---|---|---|---|---|---|---|
| Shareholdings | ||||||||||
| Reporting company | ||||||||||
| Details of specified investment shares held for purposes other than pure investment | ||||||||||
| Issue | 
                                                中山福㈱
                                                
                                             | 
                                                ㈱山善
                                                
                                             | 
                                                コクヨ㈱
                                                
                                             | 
                                                ㈱ヤマノホールディングス
                                                
                                             | 
                                                ㈱高島屋
                                                
                                             | — | — | — | — | — | 
| Number of shares | 
                                                6,935
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                21,087
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                61,313
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                2,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                6,589
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                2,751
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                2,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                60,271
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                5,200
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                20,887
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
| Carrying amount | 
                                                2,531,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                29,438,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                171,492,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                130,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,329,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,287,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                136,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                138,263,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,898,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,919,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Purpose of shareholding, overview of business alliance, quantitative effects of shareholding and reason for increase in number of shares | 
                                                取引関係の維持のためであり、持株会を通じた株式が増加しております。
                                                
                                             | 
                                                取引関係の維持のためであり、持株会を通じて株式が増加しております。
                                                
                                             | 
                                                取引関係の維持のためであり、持株会を通じて株式が増加しております。
                                                
                                             | 
                                                取引関係強化のためであります。
                                                
                                             | 
                                                取引関係の維持のためであり、持株会を通じて株式が増加しております。
                                                
                                             | — | — | — | — | — | 
| Whether issuer of aforementioned shares holds reporting company's shares | 
                                                無
                                                
                                             | 
                                                無
                                                
                                             | 
                                                無
                                                
                                             | 
                                                無
                                                
                                             | 
                                                無
                                                
                                             | — | — | — | — | — |