Quarterly Balance Sheet
| Concept | As at 2025-03-31 | As at 2024-09-30 | 
|---|---|---|
| Quarterly balance sheet | ||
| Balance sheet | ||
| Assets | ||
| Current assets | ||
| Cash and deposits | 
                                                851,507,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                762,303,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Merchandise and finished goods | 
                                                19,294,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                25,330,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Work in process | 
                                                28,741,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,382,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Raw materials and supplies | 
                                                39,774,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                102,361,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                4,499,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,029,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current assets | 
                                                1,045,152,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,126,669,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | ||
| Property, plant and equipment | 
                                                710,386,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                755,925,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Property, plant and equipment | ||
| Land | 
                                                157,071,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                157,071,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Construction in progress | 
                                                10,735,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                28,120,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | — | — | 
| Other, net | 
                                                26,121,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                32,358,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | 
                                                1,610,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,893,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | ||
| Software | 
                                                1,472,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,463,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                138,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                429,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | 
                                                29,370,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                44,036,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | ||
| Long-term prepaid expenses | 
                                                4,583,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Deferred tax assets | 
                                                14,144,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                33,522,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                10,642,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,502,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | 
                                                741,367,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                802,855,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Assets | 
                                                1,786,519,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,929,525,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | ||
| Current liabilities | ||
| Income taxes payable | 
                                                9,892,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                21,934,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                320,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                183,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | 
                                                133,997,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                206,353,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | ||
| Asset retirement obligations | 
                                                7,103,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,094,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | 
                                                7,103,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,094,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | 
                                                141,101,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                213,447,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | ||
| Shareholders' equity | ||
| Share capital | 
                                                346,497,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                346,497,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Capital surplus | 
                                                313,447,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                313,447,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retained earnings | 
                                                1,029,212,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,099,714,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Treasury shares | 
                                                -43,739,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -43,582,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Shareholders' equity | 
                                                1,645,418,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,716,077,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                1,645,418,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,716,077,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | 
                                                1,786,519,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,929,525,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |