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 | 
                                                331,910,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                254,460,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividends received | 
                                                578,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | 
                                                -1,415,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -557,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | 
                                                -81,310,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -51,866,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | 
                                                249,763,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                198,070,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | ||||||
| Purchase of property, plant and equipment | 
                                                -1,508,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -62,575,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | 
                                                -4,650,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,752,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | ||||||
| Proceeds from long-term borrowings | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                60,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Repayments of long-term borrowings | 
                                                -35,396,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -18,996,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of treasury shares | 
                                                -30,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | 
                                                -49,848,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                45,716,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Effect of exchange rate change on cash and cash equivalents | 
                                                -1,005,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                194,259,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                249,538,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                1,435,248,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,240,989,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,019,613,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                749,929,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |