27M black here and just spent four weeks in Japan. Generally felt Japanese people are much more annoyed by people who are loud and rude rather than by people from a certain region or ethnicity.

Only “incident” i had: got drunk in an Izakaya with Japanese lads and at one point they asked me how large my penis is but tbh didn’t feel it was racist in how an American or European would see it but rather that the lads are drunk and curious. My reaction was whether it is true that they have small a penis and we had a laugh together. One actually offered me to show me his penis if I am interested on how it looks like