Rebellious Joe Yabuki wanders the downtown slums. After a street fight with the yakuza to save a girl, his skills catch the eye of former boxing coach Danpei Tange, who offers to train him. Joe rejects, until he ends up in juvenile detention and suffers his first defeat by the hands of Toru Rikiishi. This rivalry ignites his passion for boxing, and Joe begins intensive training with Danpei.
