Quarterly Consolidated 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 consolidated statement of cash flows | ||||||
| Statement of cash flows | ||||||
| Cash flows from operating activities | ||||||
| Profit (loss) before income taxes | — | 
                                                373,676,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                915,636,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Depreciation | — | 
                                                153,538,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                160,423,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Impairment losses | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                22,896,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividend income | — | 
                                                -273,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -154,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest expenses | — | 
                                                5,333,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,148,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Decrease (increase) in trade receivables | — | 
                                                -356,699,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,271,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Decrease (increase) in inventories | — | 
                                                163,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -153,771,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in trade payables | — | 
                                                110,237,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                19,430,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | — | 
                                                125,586,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -85,811,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Subtotal | — | 
                                                408,922,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                410,778,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | — | 
                                                273,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                154,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest paid | — | 
                                                -5,215,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -3,974,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Income taxes paid | — | 
                                                -243,689,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -185,052,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                160,290,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                221,904,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | ||||||
| Purchase of property, plant and equipment | — | 
                                                -366,183,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -305,692,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of property, plant and equipment | — | 
                                                15,922,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                667,777,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of investment securities | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -23,289,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of shares of subsidiaries resulting in change in scope of consolidation | — | 
                                                -71,767,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | — | 
                                                841,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -69,952,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -416,673,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                560,983,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | ||||||
| Proceeds from long-term borrowings | — | 
                                                420,016,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                415,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Repayments of long-term borrowings | — | 
                                                -372,982,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -292,537,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Redemption of bonds | — | 
                                                -33,500,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -28,500,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from issuance of shares | — | 
                                                430,475,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,200,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Dividends paid | — | 
                                                -70,165,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -107,752,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Dividends paid to non-controlling interests | — | 
                                                -20,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | 
                                                757,609,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                466,444,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Effect of exchange rate change on cash and cash equivalents | — | 
                                                4,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -11,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                501,231,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,249,321,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | 
                                                2,355,784,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,854,553,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,344,846,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,095,525,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |