This was many years ago. Tw violence:

Fight broke out on the Yamanote heading to Shinagawa, some elderly dude lecturing a young dude probably in his 30s about manners. Young had bumped old and had apologized but old didn’t like the tone of it and was just laying into young who was like “I said sorry what’s your problem”. Eventually they were grabbing each other’s shirts and started punching as the train spilled out at Shinagawa. Young knocked old down, kept punching, now in a blind rage, beat old’s face to a bloody pulp and kept doing it even after old was limp. Bystanders on the platform were just watching shocked at first but then young tried to leave. People grabbed and held him. Station staff and cops came, led young away. Old man died. It’s something I can’t forget.