Very cute.
I have questions, though. If humans can turn into beastmen, and "you're born one or the other", does this mean they can mate and have viable offspring? If yes, then why was it an "inter-SPECIES" war if, supposing all prior is true, they aren't different species? Unless, also supposing mating is viable, this is just a situation of magical hijinks in classical fantasy.
Also, why is it that it's always "pure humans" vs literally any and every other animal under the sun grouped as one "tribe" of beast-people?