SO long ago I'm not sure why I'm responding lol except that this is sooo not my experience living in Nagoya and even less so in Tokyo. IF (and only if) there is not enough room for both of you, the Japanese (or at least Nagoyans) will generally play chicken with you (if in a group they will look you in the eye and do it, if alone they will look at the ground even if they've banged right into you lol, and I'm afraid I tend to lose and step into the gutter rather than do the shoulder bump which can be painful.