Quarterly Consolidated Balance Sheet
| Concept | As at 2024-09-30 | As at 2024-03-31 | 
|---|---|---|
| Quarterly consolidated balance sheet | ||
| Balance sheet | ||
| Assets | ||
| Current assets | ||
| Cash and deposits | 
                                                730,829,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                734,136,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Merchandise and finished goods | 
                                                42,068,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                45,458,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Work in process | 
                                                146,412,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                143,028,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Raw materials and supplies | 
                                                133,010,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                133,427,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                16,026,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                15,763,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current assets | 
                                                1,246,464,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,262,120,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | ||
| Property, plant and equipment | 
                                                167,337,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                135,817,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Property, plant and equipment | ||
| Buildings and structures | — | — | 
| Buildings and structures, net | 
                                                11,836,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,201,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Machinery, equipment and vehicles | — | — | 
| Machinery, equipment and vehicles, net | 
                                                2,719,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,875,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Land | 
                                                118,674,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                118,674,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | — | — | 
| Other, net | 
                                                34,107,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,066,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | ||
| Intangible assets | 
                                                2,041,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,291,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | 
                                                229,752,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                218,352,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | ||
| Investment securities | 
                                                95,058,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                95,058,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Deferred tax assets | 
                                                75,826,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                67,908,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                58,866,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                55,385,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | 
                                                399,131,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                356,461,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Assets | 
                                                1,645,596,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,618,582,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | ||
| Current liabilities | ||
| Notes and accounts payable - trade | 
                                                11,409,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,345,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Short-term borrowings | 
                                                140,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                135,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Income taxes payable | 
                                                612,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,854,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                53,429,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                64,959,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | 
                                                262,302,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                257,824,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | ||
| Long-term borrowings | 
                                                31,997,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                84,561,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retirement benefit liability | 
                                                11,341,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,763,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Asset retirement obligations | 
                                                3,131,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,122,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | 
                                                46,470,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                95,446,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | 
                                                308,773,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                353,270,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | ||
| Shareholders' equity | ||
| Share capital | 
                                                50,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                50,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Capital surplus | 
                                                1,040,407,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,040,407,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retained earnings | 
                                                248,406,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                176,894,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Treasury shares | 
                                                -1,990,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,990,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Shareholders' equity | 
                                                1,336,823,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,265,311,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                1,336,823,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,265,311,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | 
                                                1,645,596,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,618,582,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |