Quarterly Statement Of Cash Flows
| Concept | As at 2024-03-31 | 2023-10-01 to 2024-03-31 | As at 2023-09-30 | As at 2023-03-31 | 2022-10-01 to 2023-03-31 | As at 2022-09-30 | 
|---|---|---|---|---|---|---|
| Quarterly statement of cash flows | ||||||
| Statement of cash flows | ||||||
| Cash flows from operating activities | ||||||
| Subtotal | — | 
                                                -738,421,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                187,504,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest paid | — | 
                                                -1,166,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,316,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Income taxes paid | — | 
                                                -119,111,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -59,282,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                -858,505,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                131,722,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | ||||||
| Purchase of property, plant and equipment | — | 
                                                -61,083,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,562,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of investment securities | — | 
                                                -37,500,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                51,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -152,851,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -461,339,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | ||||||
| Proceeds from long-term borrowings | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                540,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Repayments of long-term borrowings | — | 
                                                -54,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -54,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from issuance of shares | — | 
                                                8,900,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                14,600,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | — | 
                                                -91,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | 
                                                454,808,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                500,600,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                -556,549,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                170,983,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | 
                                                809,095,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,365,645,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,624,915,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,453,932,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |