One day on his way home, Yomogi Asanaka, a first year student at Fujiyokidai High School, meets a mysterious man named Gauma who claims to be a 'Kaiju user'.
Suddenly, Kaiju and the giant robot Dynazenon appear.
Together with Yume Minami, Koyomi Yamanaka, and Chise Asukagawa, who also happen to be there, he gets caught up in the battle against the Kaiju.