Quarterly Consolidated Statement Of Cash Flows
| Concept | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | 2022-01-01 to 2022-12-31 | As at 2022-12-31 | As at 2021-12-31 | 
|---|---|---|---|---|---|
| Quarterly consolidated statement of cash flows | |||||
| Statement of cash flows | |||||
| Cash flows from operating activities | |||||
| Profit (loss) before income taxes | 
                                                -1,215,008,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,237,861,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Depreciation | 
                                                1,203,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,476,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Decrease (increase) in trade receivables | 
                                                32,024,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -89,761,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Decrease (increase) in inventories | 
                                                7,371,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -12,488,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Increase (decrease) in trade payables | 
                                                5,869,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,056,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                42,928,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -23,730,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Subtotal | 
                                                -1,071,232,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,208,689,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | 
                                                -2,069,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,323,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | 
                                                -5,010,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -3,240,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | 
                                                -1,069,192,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,191,009,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | |||||
| Proceeds from sale of property, plant and equipment | 
                                                173,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | 
                                                173,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | |||||
| Proceeds from issuance of shares | 
                                                554,515,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,126,292,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | 
                                                667,303,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,127,291,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                -401,715,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -63,717,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                1,325,554,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,727,270,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,790,988,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |