Fifteen-year-olds Satoyama Katsuki and his best friend, Kawakami Kyouta, decide to join Mizutani Boxing Gym to be closer to their crush, Mizutani Katsuki, a tomboy whose father owns the establishment. However, Satoyama quickly discovers that Mizutani is estranged from her father and has no love for boxing.
During a sparring match, Satoyama's hidden talent for boxing is revealed to everyone, including Mizutani. She confesses that she loves boxing but is unable to participate in it due to societal gender norms. Mizutani becomes Satoyama's trainer and manager, and he agrees to pursue the championship belt as a way to get closer to her.
As the story unfolds, it is revealed that Satoyama possesses a remarkable family history and lineage that gives him the potential to become a legendary oriental pro-boxing champion.
