I haven't read any of the other posts, so I pre-apologize if I copied someone else's answer...
But from what I've gathered, Japanese people tend to keep their space from everyone-- especially foreigners. It's a really a matter of 'comfort zones', not a dislike for people, that keep them from openly interacting...
Though I would have random people come up and do 'drive-by' photos with me, all the while asking me if I was American-- with the biggest chiizus on their faces!
And I also had little old ladies scoot away and prude up when I came around-- but I've also had little old ladies sit next to me and fan me off on park benches!
In general, I think they react pretty well to foreigners-- it's near celebrity status... Unless you're a creep, and/or ugly.
