Semi-Annual Balance Sheet
| Concept | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Semi-annual balance sheet | |||||||||||||||||||||||||||
| Balance sheet | |||||||||||||||||||||||||||
| Assets | |||||||||||||||||||||||||||
| Current assets | |||||||||||||||||||||||||||
| Cash and deposits | — | — | — | — | — | — | 
                                                1,667,921,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1,541,419,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Other | — | — | — | — | — | — | 
                                                15,646,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                12,747,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Current assets | — | — | — | — | — | — | 
                                                1,775,974,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1,650,947,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Prepaid expenses | — | — | — | — | — | — | 
                                                11,474,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                5,475,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Non-current assets | |||||||||||||||||||||||||||
| Property, plant and equipment | |||||||||||||||||||||||||||
| Buildings | — | — | — | — | — | — | 
                                                1,281,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1,281,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Accumulated depreciation | — | — | — | — | — | — | 
                                                -1,281,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                -1,281,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Buildings, net | — | — | — | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Property, plant and equipment | — | — | — | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Tools, furniture and fixtures | — | — | — | — | — | — | 
                                                89,397,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                91,921,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Accumulated depreciation | — | — | — | — | — | — | 
                                                -89,397,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                -91,920,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Tools, furniture and fixtures, net | — | — | — | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Intangible assets | |||||||||||||||||||||||||||
| Intangible assets | — | — | — | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Other | — | — | — | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Investments and other assets | |||||||||||||||||||||||||||
| Investments and other assets | — | — | — | — | — | — | 
                                                42,862,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                42,862,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Long-term prepaid expenses | — | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Non-current assets | — | — | — | — | — | — | 
                                                42,862,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                42,862,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Assets | — | — | — | — | — | — | 
                                                1,818,837,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1,693,810,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Liabilities | |||||||||||||||||||||||||||
| Current liabilities | |||||||||||||||||||||||||||
| Income taxes payable | — | — | — | — | — | — | 
                                                18,273,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                13,079,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Current liabilities | — | — | — | — | — | — | 
                                                124,866,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                128,978,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Accounts payable - other | — | — | — | — | — | — | 
                                                61,012,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                53,465,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Non-current liabilities | |||||||||||||||||||||||||||
| Non-current liabilities | — | — | — | — | — | — | 
                                                261,564,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                166,487,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Liabilities | — | — | — | — | — | — | 
                                                386,431,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                295,465,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Other liabilities | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Other liabilities | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Net assets | |||||||||||||||||||||||||||
| Share capital | — | — | — | — | — | — | 
                                                2,437,908,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1,971,019,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Shareholders' equity | |||||||||||||||||||||||||||
| Capital surplus | |||||||||||||||||||||||||||
| Legal capital surplus | — | — | — | — | — | — | 
                                                2,723,798,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                2,256,908,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Capital surplus | — | — | — | — | — | — | 
                                                2,723,798,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                2,256,908,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Retained earnings | |||||||||||||||||||||||||||
| Other retained earnings | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Retained earnings brought forward | — | — | — | — | — | — | 
                                                -3,808,501,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                -2,903,700,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Other retained earnings | |||||||||||||||||||||||||||
| Retained earnings | — | — | — | — | — | — | 
                                                -3,808,501,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                -2,903,700,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Treasury shares | — | — | — | — | — | — | 
                                                -21,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                -21,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Shareholders' equity | — | — | — | — | — | — | 
                                                1,353,183,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1,324,205,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Net assets | 
                                                1,353,183,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,808,501,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,808,501,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,437,908,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                79,223,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -21,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,432,406,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,723,798,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,723,798,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,324,205,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,256,908,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,256,908,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -21,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,903,700,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                74,139,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,971,019,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,398,344,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,903,700,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,939,252,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,799,240,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,396,545,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,225,142,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                31,411,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,225,142,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -20,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,365,134,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,799,240,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Share acquisition rights | — | — | — | — | — | — | 
                                                79,223,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                74,139,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Liabilities and net assets | — | — | — | — | — | — | 
                                                1,818,837,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1,693,810,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — |