I just read an interesting opinion piece by a Japanese professor concerning the right to vote by non-Japanese permanent residents. Check it out. I think I already knew that you can’t hold multiple citizenships if you become a citizen of Japan, but that fact struck me as interesting in this new light. I know a guy who is both a citizen of the US and of Italy, and I always thought that was cool.
In any event, letting permanent residents vote in Japan would be a big step. “Foreigners” are marginalized quite a bit, though, so it would really just be the first step of many.