Quarterly Consolidated Statement Of Cash Flows
| Concept | 2024-10-01 to 2025-03-31 | As at 2025-03-31 | 2023-10-01 to 2024-09-30 | As at 2024-09-30 | As at 2023-09-30 | 
|---|---|---|---|---|---|
| Quarterly consolidated statement of cash flows | |||||
| Statement of cash flows | |||||
| Cash flows from operating activities | |||||
| Subtotal | 
                                                -153,939,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -186,447,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividends received | 
                                                84,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                441,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | 
                                                -112,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -364,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | 
                                                -180,892,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -207,224,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | |||||
| Purchase of property, plant and equipment | 
                                                -1,472,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -5,686,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of property, plant and equipment | — | — | 
                                                170,050,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of investment securities | 
                                                -64,121,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -222,814,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | 
                                                -76,297,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -25,164,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | |||||
| Repayments of long-term borrowings | 
                                                -5,040,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -13,075,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | 
                                                -5,040,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -36,850,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                -262,229,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -269,239,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                291,593,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                553,823,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                823,062,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |