Statement Of Cash Flows
| Concept | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2023-03-31 | 
|---|---|---|---|---|---|---|---|
| Statement of cash flows | |||||||
| Statement of cash flows | |||||||
| Cash flows from operating activities | |||||||
| Profit (loss) before income taxes | 
                                                4,333,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                10,195,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                15,272,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,820,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Depreciation | — | — | 
                                                18,661,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                17,855,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Impairment losses | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                278,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in allowance for doubtful accounts | — | — | 
                                                7,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -19,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest and dividend income | — | — | 
                                                -182,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -144,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest expenses | — | — | 
                                                264,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                114,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Decrease (increase) in trade receivables | — | — | 
                                                2,035,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,350,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Decrease (increase) in inventories | — | — | 
                                                1,802,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -314,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Subtotal | — | — | 
                                                10,564,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,017,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in trade payables | — | — | 
                                                -1,805,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                858,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Income taxes paid | — | — | 
                                                -6,861,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,504,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                4,018,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,266,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest and dividends received | — | — | 
                                                183,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                143,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest paid | — | — | 
                                                -238,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -56,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from operating activities | |||||||
| Loss (gain) on sale of investment securities | — | — | 
                                                -184,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -15,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from operating activities | |||||||
| Cash flows from investing activities | |||||||
| Purchase of investment securities | — | — | 
                                                -45,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -240,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -2,067,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -16,541,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from sale of investment securities | — | — | 
                                                410,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                46,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Other, net | — | — | 
                                                -17,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from facilities maintenance and investing activities | |||||||
| Cash flows from financing activities | |||||||
| Proceeds from short-term borrowings | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                23,100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Repayments of short-term borrowings | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -23,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from issuance of bonds | — | — | 
                                                9,952,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,958,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from long-term borrowings | — | — | 
                                                18,500,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                30,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) financing activities | — | — | 
                                                -1,329,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,636,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Redemption of bonds | — | — | 
                                                -5,230,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -5,260,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Repayments of long-term borrowings | — | — | 
                                                -23,143,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -22,222,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Other, net | — | — | 
                                                -54,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -113,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net increase (decrease) in cash and cash equivalents | — | — | 
                                                788,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,610,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Effect of exchange rate change on cash and cash equivalents | — | — | 
                                                167,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                27,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash and cash equivalents | — | 
                                                9,162,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                8,374,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                9,984,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |