Quarterly Consolidated Statement Of Cash Flows
| Concept | As at 2023-03-31 | 2022-04-01 to 2023-03-31 | 2022-04-01 to 2023-03-31 | 2021-04-01 to 2022-03-31 | As at 2022-03-31 | 2021-04-01 to 2022-03-31 | As at 2021-03-31 | 
|---|---|---|---|---|---|---|---|
| Quarterly consolidated statement of cash flows | |||||||
| Statement of cash flows | |||||||
| Cash flows from operating activities | |||||||
| Profit (loss) before income taxes | — | 
                                                79,404,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                140,122,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                23,419,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -37,702,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Depreciation | — | — | 
                                                161,082,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                165,692,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in allowance for doubtful accounts | — | — | 
                                                4,631,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -60,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest and dividend income | — | — | 
                                                -10,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,038,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest expenses | — | — | 
                                                13,655,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                14,994,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Decrease (increase) in trade receivables | — | — | 
                                                -7,855,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -133,319,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Decrease (increase) in inventories | — | — | 
                                                -540,219,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                49,001,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in trade payables | — | — | 
                                                73,386,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                212,256,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Other, net | — | — | 
                                                -43,622,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                110,280,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Subtotal | — | — | 
                                                -117,361,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                391,202,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest and dividends received | — | — | 
                                                10,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,038,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest paid | — | — | 
                                                -13,283,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -14,073,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Income taxes paid | — | — | 
                                                -35,042,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -10,555,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                -165,676,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                367,611,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from investing activities | |||||||
| Purchase of property, plant and equipment | — | — | 
                                                -165,020,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -113,273,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from sale of property, plant and equipment | — | — | 
                                                4,500,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                569,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from sale of investment securities | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                30,990,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Other, net | — | — | 
                                                -2,683,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,783,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -204,814,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -83,495,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from financing activities | |||||||
| Proceeds from short-term borrowings | — | — | 
                                                277,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Repayments of short-term borrowings | — | — | 
                                                -167,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -300,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from long-term borrowings | — | — | 
                                                820,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                460,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Repayments of long-term borrowings | — | — | 
                                                -700,227,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -683,515,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Dividends paid | — | — | 
                                                -5,849,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -5,883,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Purchase of shares of subsidiaries not resulting in change in scope of consolidation | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -21,780,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) financing activities | — | — | 
                                                223,923,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -351,178,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net increase (decrease) in cash and cash equivalents | — | — | 
                                                -146,567,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -67,063,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash and cash equivalents | 
                                                422,490,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                569,057,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                636,121,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |