Quarterly Consolidated Statement Of Cash Flows
| Concept | 2024-04-01 to 2024-09-30 | As at 2024-09-30 | As at 2024-03-31 | 2023-04-01 to 2023-09-30 | As at 2023-09-30 | As at 2023-03-31 | 
|---|---|---|---|---|---|---|
| Quarterly consolidated statement of cash flows | ||||||
| Statement of cash flows | ||||||
| Cash flows from operating activities | ||||||
| Profit (loss) before income taxes | 
                                                -110,961,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -217,532,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Depreciation | 
                                                32,321,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                32,584,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividend income | 
                                                -447,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -86,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest expenses | 
                                                7,764,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                9,880,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Decrease (increase) in trade receivables | 
                                                231,674,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                294,294,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Decrease (increase) in inventories | 
                                                -51,418,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -336,261,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Increase (decrease) in trade payables | 
                                                -82,457,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                330,763,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                1,811,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,987,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Subtotal | 
                                                5,991,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,047,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividends received | 
                                                447,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                86,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | 
                                                -7,272,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -10,019,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | 
                                                -643,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -16,870,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | 
                                                -1,476,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -27,851,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | ||||||
| Purchase of property, plant and equipment | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -2,756,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of investment securities | 
                                                -532,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -354,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of investment securities | 
                                                8,991,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                253,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -531,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | 
                                                8,713,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -4,241,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | ||||||
| Proceeds from long-term borrowings | 
                                                650,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                400,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Repayments of long-term borrowings | 
                                                -895,418,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -87,246,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Dividends paid | 
                                                -52,559,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -52,727,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                -9,695,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -10,349,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | 
                                                -307,672,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                53,645,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                -300,436,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                21,551,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                997,371,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,297,808,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,325,945,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,304,393,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |