Kanichi Nishi

Originally a hot-headed juvenile delinquent, this former rival eventually evolves into Joe’s loyal trainer and primary sparring partner. After their initial violent encounter in a detention center, a deep bond forms between the two, leading Nishi to abandon his arrogant ways for a steadier life working at a grocery store. Driven by his admiration for Joe's boxing prowess, he joins the Tange gym, balancing his athletic journey with a budding romance with his boss's daughter, Noriko.