Joe isn't trying to be inspiring, he's a feral kid who fights because he has nothing else, and the show trusts you to watch him actually change. Danpei is a drunk who can't coach him legally, so their partnership becomes about two broken people deciding to stay broken together until boxing forces them to choose something else. The animation stutters and the pacing sags, but when Joe hits the ring, every punch carries the weight of someone with no other way out.

A street orphan with a quick temper finds his calling in the boxing ring. Joe Yabuki lives in the slums of Doya, settling every problem with his fists, until a fight with a local gang catches the eye of Danpei Tange, a former boxing coach turned alcoholic. Danpei sees real talent in the self-taught brawler and offers to make him the greatest boxer in Japan. Joe first writes him off as a hopeless drunk, but after Danpei saves his life, he agrees to live with him and train. Sent to a harsh juvenile home for petty crimes, Joe meets Rikiishi, who becomes his boxing rival. When Joe commits to the sport for real, Danpei's reputation as a drunk keeps him from getting a coaching license, and the road to going pro tests Joe at every step.