Suzuki Aoba, a gloomy high school freshman who has always lived an unattractive life, was enjoying his school life, even though he was occasionally beaten up by his classmate Iwase Sannosuke in what he called "play fighting".

One day, he is saved from the "play fighting" by Akasawa Kenshin, a superstar in the martial arts world who is attracting attention in the next class, but Kenshin suddenly says to him, "You're empty...", and Aoba cannot forgive him and declares that he wants to "punch him once". After being introduced by Sannosuke, Aoba enrolls in the Shark Gym, which is about to go bankrupt and is run by Tokiwa Kanenari, and enters the world of "MMA" (mixed martial arts)!

Under the guidance of his master, Amachi Wataru, he aims to reach the top of "MMA Koshien", a tournament to determine the strongest high school fighter. A group of eccentric athletes, including Tamamatsu Kota, Hazuru Yuga, Nueji Ganmaru, Hiiragi Amu, and Hachiya Mamoru, await Aoba. An unprecedented sports youth story begins here, with the protagonist from the shadows taking on mixed martial arts!