Quarterly Consolidated Statement Of Cash Flows
| Concept | 2024-01-01 to 2024-12-31 | As at 2024-12-31 | 2024-01-01 to 2024-12-31 | 2023-01-01 to 2023-12-31 | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | As at 2022-12-31 | 
|---|---|---|---|---|---|---|---|
| Quarterly consolidated statement of cash flows | |||||||
| Statement of cash flows | |||||||
| Cash flows from operating activities | |||||||
| Profit (loss) before income taxes | 
                                                1,017,439,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                999,126,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                778,616,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                820,007,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Depreciation | 
                                                147,280,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                161,158,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Amortization of goodwill | 
                                                64,626,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                64,626,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest expenses | 
                                                13,746,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                13,062,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Decrease (increase) in trade receivables | 
                                                2,042,431,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -1,501,118,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Decrease (increase) in inventories | 
                                                9,906,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -70,509,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Increase (decrease) in trade payables | 
                                                -1,016,082,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                418,975,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                -23,368,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                106,586,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Subtotal | 
                                                2,497,693,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                109,976,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | 
                                                -14,033,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -13,427,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | 
                                                2,024,950,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                234,156,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | |||||||
| Purchase of property, plant and equipment | 
                                                -888,273,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -564,408,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                -2,417,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -1,501,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | 
                                                -898,750,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -470,749,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | |||||||
| Proceeds from long-term borrowings | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                750,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Repayments of long-term borrowings | 
                                                -336,328,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -304,996,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Dividends paid | 
                                                -60,259,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -50,200,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | 
                                                -766,691,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                489,114,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Effect of exchange rate change on cash and cash equivalents | 
                                                229,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                863,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                359,736,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                253,386,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                2,108,758,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,749,021,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,495,635,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |