Yomogi Asanaka was just an ordinary high school student when he encountered a man called Gauma, who claimed himself to be a “Kaiju User”. Just after they met, the city was attacked by a Kaiju and Gauma summoned the giant robot Dynazenon to fight against it. Yomogi’s classmate Yume Minami and a local NEET Koyomi Yamanaka happened to be nearby and were accidentally caught up in the battle. Together with Yomogi, they ended up becoming Gauma's copilots for Dynazenon.
As soon as they formed a team called “Gauma Team” to protect the city from Kaijus’ attack, “Kaiju Eugenicists”, a secret society formed by teenagers with special power, stood against them and declared war on the team…