Applying clear-cutting to an even-aged pure forest is a conventional forest operation for wood production. However, this kind of operation is not suitable for sustainable management with multiple objectives. In contrast, mixed-forest is a forestation strategy that accommodates diversity. The goal of this study was to assess an operation model that transforms from an even-aged pure forest into a mixed forest. Analysis in which an even-aged pure forest of Cryptomeria japonica was cut under a fixed harvesting intensity and replanted with the native broad-leaved tree species Cinnamomum camphora were conducted. In this study, the primary income for the forest owner was derived from wood sales and carbon payments. After deducting the costs of afforestation, management, and cutting, the land expectation value was estimated. The effects of critical variables, such as cutting time, harvesting intensity, and carbon price, were analyzed. This study explored strategies by which value could be increased in the transition from an even-aged pure forest to a mixed forest. Feasible methods included reducing the costs of afforestation, management, and cutting while increasing carbon prices to increase profits from wood and carbon income. Higher harvesting intensity could contribute to greater production of Cryptomeria japonica and increase the area available for planting Cinnamomum camphora, resulting in greater profits from wood and carbon income. The net present value from market value would be from − 8,428 USD/ha to − 2,446 USD/ha and that from carbon value will be from 5,151 USD/ha to 6,895 USD/ha. However, this measure would also substantially affect forest ecology. A sole focus on increasing the production value of forestland will neglect the original goal of transforming from an even-aged pure forest into a mixed forest.