Quarterly Consolidated 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 consolidated statement of cash flows | ||||||
| Statement of cash flows | ||||||
| Cash flows from operating activities | ||||||
| Subtotal | 
                                                19,980,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                117,234,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividends received | 
                                                876,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | 
                                                -1,526,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -744,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | 
                                                -2,546,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -13,255,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | 
                                                20,158,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                105,542,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | ||||||
| Purchase of property, plant and equipment | 
                                                -2,484,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -16,195,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | 
                                                -202,414,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -15,967,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | ||||||
| Repayments of long-term borrowings | 
                                                -20,016,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -10,020,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of treasury shares | 
                                                -14,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -33,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | 
                                                -24,090,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -13,622,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                -206,346,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                75,952,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                818,576,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,024,922,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,070,332,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                994,380,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |