Sounds like your child is already feeling the difference between the cultre that she is used to at home (Japanese) and the one outside the home (Western). It might be hard for your child to get along and fill the gap. Why not talk to your child about this issue? Have you ever really sat down and asked your child what’s going on, and about how your child feels when at home and outside the home? Unless you can accurately pinpoint what’s wrong, I don’t think it’s wise to make a decision as to what course of action to take.
Do you have a good rapport with your child? If you become a friend to your child and not jsut as a parent, then he/she might open up and let you know what’s going on. Then, together you guys can work out what’s best for the child.