Major Shareholders
| Concept | 
                                    
                                        As at 2025-03-31  | 
                            
                                
                                    
                                        As at 2025-03-31  | 
                            
                                
                                    
                                        As at 2025-03-31  | 
                            
                                
                                    
                                        As at 2025-03-31  | 
                            
                                
                                    
                                        As at 2025-03-31  | 
                            
                                
                                    
                                        As at 2025-03-31  | 
                            
                                
                                    
                                        As at 2025-03-31  | 
                            
                                
                                    
                                        As at 2025-03-31  | 
                            
                                
                                    
                                        As at 2025-03-31  | 
                            
                                
                                    
                                        As at 2025-03-31  | 
                            
                                
                                    
                                        As at 2025-03-31  | 
                            
                        
|---|---|---|---|---|---|---|---|---|---|---|---|
| Major shareholders | |||||||||||
| Major shareholders | |||||||||||
| Name | 
                                        
                                             
                                                ホクシン取引先持株会
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                國分節子
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                永大産業㈱
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                米島清生
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                酒井佐知子
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                日本証券金融㈱
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                大建工業㈱
                                                
                                             
                                        
                                     | 
                                
                                    — | 
                                        
                                             
                                                兼松㈱
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                中島和信
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                ㈱池田泉州銀行
                                                
                                             
                                        
                                     | 
                                
                            
| Address | 
                                        
                                             
                                                岸和田市木材町17番地2
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                奈良県奈良市富雄川西
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                大阪市住之江区平林南2丁目10番60号
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                兵庫県宝塚市野上
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                大阪市阿倍野区阿倍野筋
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                東京都中央区日本橋茅場町1丁目2番10号
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                大阪市北区中之島3丁目2番4号
                                                
                                             
                                        
                                     | 
                                
                                    — | 
                                        
                                             
                                                東京都千代田区丸の内2丁目7番2号
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                東京都国分寺市西町
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                大阪市北区茶屋町18番14号
                                                
                                             
                                        
                                     | 
                                
                            
| Number of shares held | 
                                        
                                             
                                                941,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                710,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                1,000,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                387,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                728,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                342,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                4,227,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                16,965,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                7,522,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                674,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                430,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Shareholding ratio (excluding treasury shares) | 
                                        
                                             
                                                0.0332
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                0.0251
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                0.0353
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                0.0137
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                0.0257
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                0.0121
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                0.1491
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                0.5984
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                0.2653
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                0.0238
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                0.0152
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     |