To fulfill their deceased father's wish, siblings Takane Kiku and Takane Ryuji aim for the championship title in the boxing arena. Their sister, Kiku, serves as the trainer, while her brother, Ryuji, focuses on the role of the boxer and learns the Boomerang technique. His battles against numerous rivals have contributed to Ryuji's growth and maturation. The junior high boxing tournament has commenced, and Ryuji is set to face his arch-rival, Kenzaki Jun. The fight begins.