Consolidated Statement Of Cash Flows
| Concept | As at 2024-06-30 | 2024-01-01 to 2024-06-30 | As at 2023-12-31 | As at 2023-06-30 | 2023-01-01 to 2023-06-30 | As at 2022-12-31 | 
|---|---|---|---|---|---|---|
| Consolidated statement of cash flows | ||||||
| Statement of cash flows | ||||||
| Cash flows from operating activities | ||||||
| Subtotal | — | 
                                                -671,113,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -589,373,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest paid | — | 
                                                -1,282,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -910,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Income taxes paid | — | 
                                                -5,010,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -5,010,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                -677,388,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -595,281,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | ||||||
| Proceeds from sale of property, plant and equipment | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                82,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                82,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | ||||||
| Proceeds from issuance of shares | — | 
                                                454,390,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from short-term borrowings | — | 
                                                22,600,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                130,800,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Repayments of short-term borrowings | — | 
                                                -21,500,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -16,500,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | 
                                                455,490,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                113,359,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                -221,898,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -481,839,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | 
                                                1,103,656,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,325,554,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,245,431,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,727,270,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |