Tooru Rikiishi

Tooru Rikiishi trains out of the Shiraki gym as a welterweight boxer, fighting with a tough, hybrid brawling style. The story first finds him already locked away in the same juvenile detention center where Joe Yabuki ends up, serving time after nearly beating a spectator unconscious when the man accused him of throwing a match in his own favor, a claim that enraged him past the point of control.

When Joe challenges him without realizing he is already a professional fighter, Rikiishi knocks him out with a single punch, an encounter that ends up pushing Joe to finally take boxing seriously, if only so he can one day beat Rikiishi himself. Rikiishi is seen as one of the most promising young boxers anywhere, trained in part by Youko Shiraki, and his talent makes their eventual rematch one of the series' biggest moments.

That rematch, fought once both men have turned professional, ends in a brutal battle that Rikiishi wins by decision, but the extreme weight-cutting he put his body through to make the match, combined with the damage from the fight itself, costs him his life shortly afterward. His death marks Joe forever, leaving him unable to aim for an opponent's head again for a long stretch of his career, a scar that follows Joe through the rest of the story.