I think if you live in any country long enough , you will run into someone who is trouble. Although it was rare in Japan , once in a while a very drunk man would get loud. In my two years , the only one I really remember was a drunk yakuza with a knife was very angry my 5 Japanese female friends were with a gaijin. Lucky for me , when I approached him , he ran away. This was during the early 70's and I considered Japan the safest place I'd ever been.
I agree with Uncle Frank. What exactly are you hoping to understand by asking this question?
It's possible to have bad experiences anywhere, and with people of any nationality.
What would make a bad experience unique or significant just because the person in question happened to be Japanese?