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 | 
|---|---|---|---|---|---|---|---|
| Consolidated statement of cash flows | |||||||
| Statement of cash flows | |||||||
| Cash flows from operating activities | |||||||
| Profit (loss) before income taxes | 
                                                240,114,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                282,861,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                54,975,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                140,037,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Depreciation | 
                                                96,769,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                84,580,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Amortization of goodwill | 
                                                16,544,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                14,454,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Increase (decrease) in allowance for doubtful accounts | 
                                                1,933,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,507,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividend income | 
                                                -1,391,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -2,731,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest expenses | 
                                                6,560,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                7,390,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Increase (decrease) in provision for bonuses | 
                                                212,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,459,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Increase (decrease) in retirement benefit liability | 
                                                1,587,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,355,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Share of loss (profit) of entities accounted for using equity method | 
                                                33,432,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Decrease (increase) in trade receivables | 
                                                -175,107,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -236,699,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Subtotal | 
                                                269,281,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                559,129,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Decrease (increase) in inventories | 
                                                -119,082,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                143,563,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | 
                                                -46,993,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -85,271,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | 
                                                198,288,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                393,624,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Increase (decrease) in trade payables | 
                                                233,925,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                212,668,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                26,091,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -28,572,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividends received | 
                                                1,457,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                2,731,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Loss (gain) on sale of non-current assets | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                4,263,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | 
                                                -6,637,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -7,413,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | |||||||
| Proceeds from withdrawal of time deposits | 
                                                10,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of property, plant and equipment | 
                                                -5,541,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -1,641,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of property, plant and equipment | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                64,235,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of investment securities | 
                                                -586,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -440,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | 
                                                -30,748,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                10,024,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of investment securities | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                16,500,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of shares of subsidiaries resulting in change in scope of consolidation | 
                                                -2,258,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -51,117,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                -241,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                240,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | |||||||
| Purchase of treasury shares | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -33,603,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Dividends paid | 
                                                -68,337,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -59,032,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from long-term borrowings | 
                                                100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Repayments of long-term borrowings | 
                                                -252,500,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -271,755,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Redemption of bonds | 
                                                -3,500,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | 
                                                -333,254,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -384,379,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Repayments of lease liabilities | 
                                                -8,922,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -5,670,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                4,056,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                -165,714,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                19,269,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                2,358,821,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                2,524,536,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,505,267,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |