Errors in writing, voluntary changes by the bearers, modifications for language reasons... There are many reasons why the surname Mankoju may have undergone changes or modifications, and from those modifications, surnames similar to Mankoju may have appeared, as we can see.
Discerning whether the surname Mankoju or any of the surnames similar to Mankoju came first is not always easy. There are many reasons that could have led to the surname Mankoju being written or pronounced differently, giving rise to a new, different surname Mankoju with a common root.