Quarterly Statement Of Cash Flows
| Concept | 2024-10-01 to 2025-03-31 | As at 2025-03-31 | As at 2024-09-30 | 2023-10-01 to 2024-03-31 | As at 2024-03-31 | As at 2023-09-30 | 
|---|---|---|---|---|---|---|
| Quarterly statement of cash flows | ||||||
| Statement of cash flows | ||||||
| Cash flows from operating activities | ||||||
| Profit (loss) before income taxes | 
                                                2,489,284,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,937,515,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Depreciation | 
                                                31,812,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                20,787,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest expenses | 
                                                371,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                557,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Decrease (increase) in trade receivables | 
                                                -198,401,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -131,930,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                369,666,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                195,786,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Subtotal | 
                                                2,171,096,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,002,775,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | 
                                                -352,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -581,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | 
                                                -1,183,924,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,557,027,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | 
                                                991,887,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,445,208,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | ||||||
| Purchase of property, plant and equipment | 
                                                -16,112,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -92,116,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                -21,636,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -134,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | 
                                                -125,180,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -116,114,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | ||||||
| Repayments of long-term borrowings | 
                                                -20,970,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -20,970,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of treasury shares | 
                                                -43,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -306,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | 
                                                -7,738,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                43,444,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Effect of exchange rate change on cash and cash equivalents | 
                                                -385,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                858,583,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,372,539,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                11,033,257,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,174,674,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                10,802,967,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,430,428,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |