Ashita no Joe 2: The Anime Super Remix

Troubled young guy Joe Yabuki escapes from an orphanage where he is cared for. While he is lost in the slums of Tokyo, he comes upon Danpei, who used to be a boxing trainer. Later, Joe is arrested and transferred to a temporary jail, where he fights with Nishi, who would eventually become his best friend and the leader of a gang of hooligans. After that, he and Nishi travel to a juvenile prison many kilometers outside Tokyo. There, Joe meets Rikiishi, formerly a boxing prodigy, and the two begin to compete against each other. They fight against one another, during which Rikiishi dominates Joe up until the point where Joe hits him with a cross-counter, which ultimately results in both of them being knocked out. Boxing becomes popular among the other convicts as a result of this development. Both Joe and Rikiishi have sworn to fight each other again.