Statement Of Cash Flows
| Concept | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2023-03-31 | 2022-04-01 to 2023-03-31 | 2022-04-01 to 2023-03-31 | As at 2022-03-31 | 
|---|---|---|---|---|---|---|---|
| Statement of cash flows | |||||||
| Statement of cash flows | |||||||
| Cash flows from operating activities | |||||||
| Profit (loss) before income taxes | 
                                                1,417,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,037,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                695,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                767,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Depreciation | 
                                                2,233,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,893,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividend income | 
                                                -115,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -16,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest expenses | 
                                                77,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                43,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Foreign exchange losses (gains) | 
                                                -107,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                29,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Loss (gain) on sale of property, plant and equipment | 
                                                -2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in provision for bonuses | 
                                                12,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Decrease (increase) in trade receivables | 
                                                -6,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -378,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Decrease (increase) in inventories | 
                                                -89,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -359,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in trade payables | 
                                                -460,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                823,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Subtotal | 
                                                2,813,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                2,871,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | 
                                                -180,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                258,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Income taxes paid | 
                                                -314,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -179,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | 
                                                2,685,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                2,667,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | 
                                                115,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                16,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest paid | 
                                                -77,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -43,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from operating activities | |||||||
| Loss (gain) on sale of investment securities | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -17,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from operating activities | |||||||
| Cash flows from facilities maintenance and investing activities | |||||||
| Purchase of property, plant and equipment | 
                                                -2,733,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -4,122,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of property, plant and equipment | 
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of investment securities | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                17,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | 
                                                -1,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -61,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | |||||||
| Net cash provided by (used in) investing activities | 
                                                -2,688,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -4,195,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | |||||||
| Purchase of treasury shares | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Dividends paid | 
                                                -51,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -51,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from long-term borrowings | 
                                                1,300,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                4,434,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | 
                                                -622,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                2,800,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Repayments of long-term borrowings | 
                                                -1,681,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -1,706,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Effect of exchange rate change on cash and cash equivalents | 
                                                311,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                225,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                -312,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,496,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                5,258,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,571,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,075,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |