April 1, 1970

Joe Yabuki is a troubled youth, whose only solution to problems is throwing punches at them. What he lacks in manners and discipline, he makes up for with his self-taught fighting skills. One day, while wandering the slums of Doya, Joe gets into a fight with the local gang. Although greatly outnumbered, he effortlessly defeats them, drawing the attention of Danpei Tange—a former boxing coach turned alcoholic. Seeing his potential, he offers to train Joe into Japan's greatest boxer. At first, Joe dismisses Danpei as a hopeless drunk; but after the trainer saves his life, he agrees to live with him and learn the art of boxing. Unfortunately, Joe's personality makes him an unruly student, and he often falls back to his old ways. To survive the harsh world of his new career, Joe needs to trust his mentor and master the techniques taught to him. However, the road to becoming a professional boxer is rife with struggles that will test his mettle to the end.

October 13, 1980

Yabuki Joe is left downhearted and hopeless after a certain tragic event. In attempt to put the past behind him, Joe leaves the gym behind and begins wandering. On his travels he comes across the likes of Wolf Kanagushi and Goromaki Gondo, men who unintentionally fan the dying embers inside him, leading him to putting his wanderings to an end. His return home puts Joe back on the path to boxing, but unknown to himself and his trainer, he now suffers deep-set issues holding him back from fighting. In attempt to quell those issues, Carlos Rivera, a world renowned boxer is invited from Venezuela to help Joe recover.