Consolidated Balance Sheet
| Concept | As at 2024-06-30 | As at 2023-12-31 | 
|---|---|---|
| Consolidated balance sheet | ||
| Balance sheet | ||
| Assets | ||
| Current assets | ||
| Cash and deposits | 
                                                1,301,058,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,867,264,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Accounts receivable - trade | 
                                                123,317,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                117,144,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Supplies | 
                                                103,521,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                87,863,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                42,188,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                48,495,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Advance payments to suppliers | 
                                                277,793,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                17,192,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current assets | 
                                                1,847,879,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,137,959,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | 
                                                217,726,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                235,411,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | 
                                                137,926,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                138,890,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                150,763,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                150,191,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -12,836,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -11,301,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | ||
| Property, plant and equipment | ||
| Property, plant and equipment | 
                                                14,328,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,010,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | ||
| Other | 
                                                3,757,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,224,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other intangible assets | ||
| Intangible assets | 
                                                65,471,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                86,510,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | ||
| Assets | 
                                                2,065,605,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,373,371,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | ||
| Non-current liabilities | ||
| Long-term borrowings | 
                                                429,952,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                269,476,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Bonds payable | 
                                                660,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                24,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | 
                                                1,113,952,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                899,598,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | ||
| Current portion of long-term borrowings | 
                                                19,048,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,524,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Income taxes payable | 
                                                10,549,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,708,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Accounts payable - other | 
                                                49,045,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                161,362,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                17,008,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,412,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | 
                                                95,651,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                194,008,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | 
                                                1,209,603,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,093,606,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | ||
| Shareholders' equity | 
                                                850,107,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,279,101,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Share capital | 
                                                877,469,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                831,617,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Capital surplus | 
                                                2,935,708,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,889,857,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retained earnings | 
                                                -2,963,070,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,442,372,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Treasury shares | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | 
                                                -34,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -36,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation difference on available-for-sale securities | 
                                                -34,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -36,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Share acquisition rights | 
                                                5,929,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                699,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                856,001,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,279,764,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | 
                                                2,065,605,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,373,371,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | ||
| Shareholders' equity | ||
| Valuation and translation adjustments |