Consolidated Balance Sheet
| Concept | As at 2025-03-31 | As at 2024-09-30 | 
|---|---|---|
| Consolidated balance sheet | ||
| Balance sheet | ||
| Assets | ||
| Current assets | ||
| Cash and deposits | 
                                                5,347,494,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,827,584,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Work in process | 
                                                421,954,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,146,878,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Raw materials and supplies | 
                                                28,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                28,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                877,700,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                860,628,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -38,468,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -35,420,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current assets | 
                                                34,746,320,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                22,788,472,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | ||
| Property, plant and equipment | ||
| Buildings and structures | — | — | 
| Buildings and structures, net | 
                                                567,215,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                476,725,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Own-used assets | ||
| Land | 
                                                546,234,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                546,234,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | — | — | 
| Other, net | 
                                                2,091,634,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,413,405,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Property, plant and equipment | 
                                                4,486,024,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,266,233,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | ||
| Goodwill | 
                                                307,782,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                342,775,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other intangible assets | ||
| Other | 
                                                396,079,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                351,776,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | 
                                                2,089,356,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,212,065,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Software | 
                                                1,385,494,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,517,513,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | ||
| Investment securities | 
                                                4,733,711,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,851,933,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                2,413,829,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,433,571,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -133,623,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -138,623,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | 
                                                7,013,917,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,146,882,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | 
                                                13,589,298,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                13,625,181,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Assets | 
                                                48,335,618,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                36,413,653,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | ||
| Non-current liabilities | 
                                                5,151,888,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,217,112,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Bonds payable | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                50,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Long-term borrowings | 
                                                141,902,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                166,862,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retirement benefit liability | 
                                                3,327,046,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,377,941,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | 
                                                20,174,433,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,989,283,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Short-term borrowings | 
                                                11,200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,500,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Notes and accounts payable - trade | 
                                                2,293,282,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,836,112,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | 
                                                25,326,322,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                15,206,395,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Shareholders' equity | 
                                                20,750,088,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                18,975,734,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Share capital | 
                                                1,673,778,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,673,778,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Capital surplus | 
                                                2,694,761,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,681,318,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retained earnings | 
                                                16,512,434,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                14,756,176,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Treasury shares | 
                                                -130,886,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -135,538,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | 
                                                1,982,279,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,977,409,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation difference on available-for-sale securities | 
                                                1,829,717,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,806,050,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Foreign currency translation adjustment | 
                                                26,845,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                19,753,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-controlling interests | 
                                                276,929,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                254,113,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                23,009,296,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                21,207,257,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | 
                                                48,335,618,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                36,413,653,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | ||
| Current liabilities | ||
| Current portion of long-term borrowings | 
                                                52,128,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                51,627,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Income taxes payable | 
                                                1,342,472,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                670,795,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current portion of bonds payable | 
                                                50,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provisions | ||
| Provision for bonuses | 
                                                1,537,595,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,758,831,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provisions | 
                                                30,527,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                175,320,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                3,218,484,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,015,921,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | ||
| Other | 
                                                1,682,939,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,622,308,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | ||
| Shareholders' equity | ||
| Valuation and translation adjustments | ||
| Remeasurements of defined benefit plans | 
                                                125,716,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                151,605,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |