[steven]

I've seen mixed/foreign kids in schools and some do get bullied just because of that fact. Some kids take it in stride and are cool about it while other kids are more negatively affected by it. I think it's one of those things... if the kid can't speak their "mother tongue" they are weird. If they can speak it, they are weird. (so it's like a lose-lose situation). I'm also sad to say that teachers don't seem to respect foreign students as much. If you can't speak Japanese well the teachers will probably look down on you.

Some elementary schools do have uniforms by the way.

I think that starting at elementary school is a good thing though. I think, as Nyororin said, that the teachers will be accommodating to your children. I think middle schools are less forgiving though.