Joe Yabuki is a restless young man who tends to solve every problem with his fists. Though he lacks manners and self-control, his natural, self-taught fighting ability more than compensates.
While wandering the Doya slums, Joe picks a fight with a local gang. Despite being heavily outnumbered, he easily defeats them, catching the eye of Danpei Tange—a former boxing coach who has since turned to alcohol. Danpei sees Joe's raw talent and wants to train him to become Japan's greatest boxer. Initially, Joe writes Danpei off as a hopeless drunk, but after the trainer saves his life, he agrees to live with him and learn boxing. However, Joe's stubborn personality makes him a difficult student, and he often slips back into his old habits.
To make it in the brutal world of professional boxing, Joe must learn to trust his mentor and master the techniques he's taught. But the path to becoming a pro is full of challenges that will push him to his absolute limits.
