Unfriendliest place I've been is probably Romania. We were taking stuff to their orphanages and hospitals and their thanks was to lob bricks and used syringes at us.

Most of what I know about Japan and racism comes from Tony Parson's Man and Boy. Fair to say he's not keen and discusses the word "gaijin" at some length. Nonetheless it remains the one place in the world I must visit before I die...