Sure, they are ferociously xenophobic, but if everybody is Japanese, and they are racist against non-Japanese, then it's not exactly a significant problem for Japanese students.

I'm somewhat reminded of the little podunk Maine town I grew up in; people were racist as all hell, but there was nobody to be racist to, because the entire county was white-trash WASPs and French-Canadians, and those two groups were so mixed together that nobody could sling a slur without hitting themselves with it.