january utc well after ww they had already struck a deal to return japanese colonies back to either ro china or korea with the exception of okinawa which btw was itself influenced by different groups actually ethnicity and culture are not good arguments considering the of taiwanese are hoklos and hakka both classified as a branch of southern han while the rest is various mainlanders and mixed aborigines culturally they're a typical east asian nation the reason why they're separate is because they were founded by the refugees of the roc making them a separate nation