This game was awesome! I'm so happy I finally got to play it! :)
The characters were awesome (especially Nora) and the story was very in-depth. It pulled you in and really got you invested in the characters and the differences in their views and how it affected their lives.
The English translation was ok in some parts but not as good or terrible in others. I'm not sure if you are interested but I can write a better translation in a word file and send it to you. I can tell you really tried and I appreciate it because most don't.
As far as the plot, you call them yokai but they aren't. What your characters are described as are what's called were- beasts. More powerful yokai have a human form they can change into. They usually use it to trick humans in some way. They do not feel large amounts of pain doing it nor do they become a completely separate being who is unable to control their "non human" form. They are born not human so saying that they have to learn how to control how they are born is a bit weird. Were-beasts however have two forms. Their default form is human. They can change into an animal but it is painful and they do have to learn to control it.
I can still completely love this game but please do more research on the subject unless you intended it to be something from a parallel universe type situation where yokai are something completely different.