Hitotsuya Yuu is a young man with a single-minded ambition: to become a world-class boxer. His immediate challenge is finding a gym that can shape his raw potential into championship form. The first gym he stumbles upon is a small, dilapidated facility that he ends up rescuing from its creditors. The strange old owner, however, warns him not to train there. Akagi Tetsu, a former champion who once trained at that same gym, notices Yuu and follows him to another training facility. There, Yuu demonstrates immense natural talent and fierce determination, impressing Tetsu.

The story takes a dramatic turn when Tetsu and Yuu watch a television report about a world-famous boxing trainer known as the Kaiser. This Japanese trainer has produced numerous champions but is driven entirely by profit, showing no genuine care for his fighters. He has just abandoned another champion for financial gain. The trainer's full nickname is Kaiser Hitotsuya. Upon hearing this, Tetsu realizes that Yuu is burning with overwhelming rage, apparently directed at his namesake. The narrative is set in the world of Japanese boxing, focusing on gym culture, training regimens, and the competitive ring. The central conflict revolves around Yuu's quest for greatness and his deep-seated, personal animosity toward the Kaiser, suggesting a familial or symbolic connection that drives the plot forward. The art style blends the bold lines and dramatic action of 1970s shonen sports manga with a modern, tongue-in-cheek sense of humor. Notable arcs likely involve Yuu's progression through the boxing ranks, his evolving relationship with Tetsu, and the eventual confrontation with the Kaiser and the secrets behind their shared name.