High school student Yomogi Asanaka meets Gauma, a "kaiju user" who defends their city from kaiju attacks with the robot Dynazenon and ropes Yomogi into the battle.

Yomogi and Koyomi try combining Dyna Soldier and Dyna Striker; Gauma tries to capture Sizumu while everyone is at the beach; Sizumu is summoned by the other Kaiju Eugenicists.