Statement Of Cash Flows
| Concept | 2023-04-01 to 2023-09-30 | As at 2023-09-30 | As at 2023-03-31 | 2022-04-01 to 2022-09-30 | As at 2022-09-30 | As at 2022-03-31 | 
|---|---|---|---|---|---|---|
| Statement of cash flows | ||||||
| Statement of cash flows | ||||||
| Cash flows from operating activities | ||||||
| Profit (loss) before income taxes | 
                                                -87,378,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -370,071,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Depreciation | 
                                                47,277,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                59,932,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Increase (decrease) in allowance for doubtful accounts | 
                                                -10,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -102,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest expenses | 
                                                1,430,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,354,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Increase (decrease) in provision for retirement benefits | 
                                                -5,593,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -17,796,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Increase (decrease) in provision for bonuses | 
                                                -6,216,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -6,077,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Decrease (increase) in trade receivables | 
                                                25,024,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                46,560,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Decrease (increase) in inventories | 
                                                2,456,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,738,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Subtotal | 
                                                60,012,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -290,701,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Increase (decrease) in trade payables | 
                                                383,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -26,862,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                -3,528,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                15,114,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | 
                                                -36,512,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -41,280,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | 
                                                -13,212,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -334,627,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | 
                                                -630,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,413,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from operating activities | ||||||
| Increase (decrease) in accounts payable - other | 
                                                -20,987,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -46,277,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from operating activities | ||||||
| Cash flows from investing activities | ||||||
| Purchase of property, plant and equipment | 
                                                -75,312,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -107,350,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | 
                                                -41,345,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -70,884,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                -2,328,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -2,300,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from facilities maintenance and investing activities | ||||||
| Cash flows from financing activities | ||||||
| Proceeds from short-term borrowings | 
                                                22,500,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                52,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Repayments of short-term borrowings | 
                                                -38,335,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -54,011,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from long-term borrowings | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                69,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | 
                                                -36,383,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                40,398,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Repayments of long-term borrowings | 
                                                -20,455,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -25,486,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                -90,941,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -365,113,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                284,387,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                375,329,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                603,426,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                968,540,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |