I never knew something like this existed *w* Wow!
Well, I can at least tell you that Europe definitely doesn't have tropical storms. So it's probably really East Asia :) And as far as I know, the forest that is around No.6 is probably natural? The Mao Forest was at least ... But you're right - mountains are a good hint ^^
As far as I know (and I don't know much) Korea would probably be too tropical? I mean, it's never stated that the climate around No.6 is humid or anything. And if I think of Korea I kind of have the image of really humid and hot summers ... I could be wrong though.