Quarterly Statement Of Cash Flows
| Concept | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2023-03-31 | 
|---|---|---|---|---|---|---|---|
| Quarterly statement of cash flows | |||||||
| Statement of cash flows | |||||||
| Cash flows from operating activities | |||||||
| Profit (loss) before income taxes | 
                                                738,732,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                819,387,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,083,890,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                691,180,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Depreciation | — | — | 
                                                805,271,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                729,602,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest and dividend income | — | — | 
                                                -30,909,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -26,115,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest expenses | — | — | 
                                                1,525,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,613,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Decrease (increase) in trade receivables | — | — | 
                                                -130,642,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -205,294,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Decrease (increase) in inventories | — | — | 
                                                -570,558,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -19,365,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in trade payables | — | — | 
                                                90,929,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -117,592,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Other, net | — | — | 
                                                -133,163,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                45,804,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Subtotal | — | — | 
                                                696,394,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,359,546,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest and dividends received | — | — | 
                                                28,266,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                26,978,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest paid | — | — | 
                                                -1,525,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,613,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Income taxes paid | — | — | 
                                                -428,230,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -114,097,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                294,904,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,274,204,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from investing activities | |||||||
| Purchase of securities | — | — | 
                                                -4,000,316,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -6,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Purchase of property, plant and equipment | — | — | 
                                                -1,269,572,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -789,956,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from sale of property, plant and equipment | — | — | 
                                                19,322,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,996,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Purchase of investment securities | — | — | 
                                                -1,524,795,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -110,720,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from sale of investment securities | — | — | 
                                                836,368,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                734,666,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Other, net | — | — | 
                                                -14,388,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -13,574,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -864,578,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -193,394,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from financing activities | |||||||
| Purchase of treasury shares | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Dividends paid | — | — | 
                                                -194,801,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -115,564,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) financing activities | — | — | 
                                                -217,125,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -135,291,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Effect of exchange rate change on cash and cash equivalents | — | — | 
                                                43,764,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                38,522,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net increase (decrease) in cash and cash equivalents | — | — | 
                                                -743,033,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                984,041,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash and cash equivalents | — | 
                                                4,891,829,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,634,863,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,650,822,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |