Consolidated Balance Sheet
| Concept | As at 2024-09-30 | As at 2024-03-31 | 
|---|---|---|
| Consolidated balance sheet | ||
| Balance sheet | ||
| Assets | ||
| Current assets | ||
| Cash and deposits | 
                                                5,460,546,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,489,404,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                353,599,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                461,550,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -600,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -600,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current assets | 
                                                21,297,590,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                21,156,213,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Money held in trust | 
                                                2,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | 
                                                1,675,048,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,522,661,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | 
                                                861,975,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                753,334,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investment securities | 
                                                95,230,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                95,230,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Guarantee deposits | 
                                                317,017,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                241,497,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Deferred tax assets | 
                                                428,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                380,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                21,728,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                36,607,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | ||
| Property, plant and equipment | 
                                                789,685,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                745,697,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Property, plant and equipment | ||
| Intangible assets | ||
| Intangible assets | 
                                                23,386,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                23,628,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | ||
| Assets | 
                                                22,972,638,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                22,678,874,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | ||
| Non-current liabilities | 
                                                528,339,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                521,990,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | 
                                                13,624,323,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,958,150,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | 
                                                14,152,663,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                13,480,140,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Shareholders' equity | 
                                                8,819,975,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,198,733,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Share capital | 
                                                344,457,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                344,457,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Capital surplus | 
                                                314,730,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                314,730,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retained earnings | 
                                                8,485,149,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,892,865,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Treasury shares | 
                                                -324,362,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -353,319,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                8,819,975,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,198,733,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | 
                                                22,972,638,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                22,678,874,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | ||
| Current liabilities | ||
| Income taxes payable | 
                                                128,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provisions | ||
| Provision for bonuses | 
                                                297,304,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                282,175,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                416,404,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                341,211,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | ||
| Other | 
                                                31,211,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                48,229,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | ||
| Shareholders' equity |