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 | 
                                                421,083,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                393,919,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -32,533,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,762,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Depreciation | 
                                                16,507,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                18,768,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Impairment losses | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                11,967,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Amortization of goodwill | 
                                                371,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividend income | 
                                                -31,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -3,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest expenses | 
                                                6,101,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                5,630,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Increase (decrease) in provision for bonuses | 
                                                139,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                615,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Share of loss (profit) of entities accounted for using equity method | 
                                                26,702,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                12,854,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Subtotal | 
                                                236,287,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -272,882,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Decrease (increase) in trade receivables | 
                                                16,904,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -47,821,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | 
                                                -32,364,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -48,829,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Decrease (increase) in inventories | 
                                                -49,513,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -101,854,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | 
                                                197,852,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -345,339,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Increase (decrease) in trade payables | 
                                                -25,400,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -17,019,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                -91,348,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -54,594,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividends received | 
                                                31,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Loss (gain) on sale of non-current assets | 
                                                -5,412,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -17,006,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | 
                                                -6,101,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -5,630,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Compensation paid for damage | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -18,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | |||||||
| Purchase of property, plant and equipment | 
                                                -55,969,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -65,280,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of property, plant and equipment | 
                                                18,031,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                52,101,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | 
                                                -192,411,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -26,270,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | |||||||
| Proceeds from issuance of shares | 
                                                24,860,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                592,327,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Repayments of short-term borrowings | 
                                                -9,578,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -3,549,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Repayments of long-term borrowings | 
                                                -114,264,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -58,315,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | 
                                                -99,166,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                533,111,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Repayments of lease liabilities | 
                                                -368,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -368,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Effect of exchange rate change on cash and cash equivalents | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                -93,725,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                161,501,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                190,414,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                284,139,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                122,638,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |