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 | 
                                                -846,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -2,202,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,312,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,640,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Depreciation | — | — | 
                                                2,249,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,486,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in allowance for doubtful accounts | — | — | 
                                                1,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest and dividend income | — | — | 
                                                -140,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -107,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest expenses | — | — | 
                                                136,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                134,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in provision for bonuses | — | — | 
                                                -29,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -10,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Decrease (increase) in trade receivables | — | — | 
                                                1,682,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -876,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Decrease (increase) in inventories | — | — | 
                                                458,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                530,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Subtotal | — | — | 
                                                2,835,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,947,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in trade payables | — | — | 
                                                -2,188,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -489,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Income taxes paid | — | — | 
                                                -627,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -670,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Other, net | — | — | 
                                                -476,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                967,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                2,208,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,315,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest and dividends received | — | — | 
                                                139,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                106,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest paid | — | — | 
                                                -138,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -133,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from operating activities | |||||||
| Loss (gain) on sale of investment securities | — | — | 
                                                -14,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Loss (gain) on sale of non-current assets | — | — | 
                                                -11,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                51,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from operating activities | |||||||
| Cash flows from investing activities | |||||||
| Purchase of investment securities | — | — | 
                                                -196,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -6,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -2,314,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,628,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from sale of investment securities | — | — | 
                                                20,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Other, net | — | — | 
                                                7,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from facilities maintenance and investing activities | |||||||
| Cash flows from financing activities | |||||||
| Purchase of treasury shares | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Dividends paid | — | — | 
                                                -104,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -90,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from long-term borrowings | — | — | 
                                                2,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                230,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) financing activities | — | — | 
                                                -212,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,370,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Repayments of long-term borrowings | — | — | 
                                                -1,214,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,835,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Effect of exchange rate change on cash and cash equivalents | — | — | 
                                                290,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                201,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net increase (decrease) in cash and cash equivalents | — | — | 
                                                -27,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                519,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash and cash equivalents | — | 
                                                5,243,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,271,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,752,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |