Semi-Annual 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 | 
|---|---|---|---|---|---|
| Semi-annual consolidated statement of cash flows | |||||
| Statement of cash flows | |||||
| Cash flows from operating activities | |||||
| Subtotal | 
                                                18,588,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                335,889,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividends received | 
                                                19,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                13,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | 
                                                -4,570,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -4,312,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | 
                                                -162,858,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -122,005,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | 
                                                -148,820,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                209,584,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | |||||
| Purchase of property, plant and equipment | 
                                                -5,269,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -2,327,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of investment securities | 
                                                -90,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | 
                                                -604,417,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -47,922,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | |||||
| Proceeds from long-term borrowings | 
                                                550,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                250,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from issuance of bonds | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                197,482,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Repayments of long-term borrowings | 
                                                -177,443,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -154,701,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Redemption of bonds | 
                                                -40,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -20,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from issuance of shares | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                560,110,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | 
                                                333,951,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                826,690,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                -419,286,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                988,352,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                1,738,947,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,158,234,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,169,882,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |