Osaka would be second, and I'm pretty Sapporo or Nagoya are the third. The the gap between Tokyo & Osaka is huge though -- Osaka is like half the population at most.I know I'm a few weeks late here, but dude... Fukuoka is not the second largest city in Japan. It's number eight. Did you actually get around Japan when you were here, do did you just say in Kyushu???
I think it's the further South you go (or at least as I've been told), with Kyushu being the culmination of all things yasashii. I guess in Wakanai Hokkaido you can get punched in the face by a complete stranger.It leads me to believe that the further west you go from Tokyo, the friendlier people are.