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 | 
                                                62,022,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                286,939,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividends received | 
                                                653,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                61,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | 
                                                -5,101,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -2,669,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | 
                                                -66,166,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -54,865,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | 
                                                -8,592,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                229,465,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | ||||||
| Purchase of property, plant and equipment | 
                                                -70,124,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -25,636,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of property, plant and equipment | 
                                                680,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                30,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                -1,530,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,175,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | 
                                                -84,560,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -32,804,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | ||||||
| Proceeds from long-term borrowings | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                300,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Repayments of long-term borrowings | 
                                                -171,869,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -233,174,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from issuance of shares | 
                                                213,440,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                -3,516,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -3,900,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | 
                                                238,054,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                112,925,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Effect of exchange rate change on cash and cash equivalents | 
                                                -295,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,032,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                144,606,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                308,554,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                1,160,187,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,015,581,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,287,093,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                978,538,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |