High school student Yomogi Asanaka meets a mysterious young man named Gauma, who claims to be a kaiju user. When a kaiju attacks the city, Gauma summons giant robot Dynazenon and his classmates are caught up in the battle.

Gauma tells Yomogi, Yume, and Koyomi that Dynazenon chose them because of their aptitude, and they must begin training as the terrorist kaiju users will attack again.

怪獣優生思想の一人、ジュウガから、かつてガウマに裏切られたという話を聞かされる蓬。ガウマに不信感を抱く蓬たちだが心揺らぐままに怪獣との戦いに臨むことになってしまう。心を一つにしなければダイナゼノンは真の力を引き出せない。