Just a note - and I am sorry to derail this conversation - but in my experience, Non-Japanese residents do not have to be outsiders in Japan.
The people who raise that point the most, in my experience, are English teachers who don't speak Japanese, or have had some kind of privileged background. I wasn't part of either in North America; at this point, I would be hard pressed to point at too many things that are particularly different for me and my Japanese co-workers.
If you do speak Japanese and have the desire to be a part of the community, you can be part of non-political society. I know plenty of non-Japanese who can participate in everything (except for voting, which is admittedly a big thing).
Some people point to police harassment (and I have experienced it), but I have seen Japanese people pulled over to have their bags searched and their cycle registration checked. It's a different norm.
That's not to say it is a great thing to be active in Japanese society. Being part of the PTA is a pain in the rear. There is plenty of meaningless inefficiency in "group activities". Everyone takes the same days off and you need to book together time months in advance. But if you want to be in the in-circle, and want to be part of traditional celebrations, you can. (Especially in Tokyo)
On the other hand, as a non-Christian who worked for a company in Salt Lake City, I doubt I could be a part of society there in the same way that I am here. I really liked my co-workers in Provo, more than even my co-workers at some companies in Japan. They were interesting and fun to be around, even when we had different political beliefs.
However, I doubt I could ever be a close friend to any of them because they had beliefs I didn't share, and couldn't share.
It's not like Japan (or Tokyo at least); if you are decent enough at the language, you can slip into groups and be a normal member of society.