After encountering the Mini Kaiju, Ibuki rushes around the university looking for a place to hide it. Meanwhile, Kyoko Shiga, an investigator from the mysterious organization UTTF, begins to take action against the kaiju threat and contacts Professor Minobe of Meishin University. Ibuki breathes a sigh of relief upon finally finding a hiding place for the Mini Kaiju—but his relief is short-lived as a welcome party for his joining of the Astronomy Club suddenly begins!?

Tossed around by two fierce kaiju, Teo completely exhausts his energy... To make matters worse, the kaiju are now marching straight toward Meishin University!? As chaos spreads, the Mini Kaiju goes missing! With the members of the Astronomy Club (including Ibuki), Minobe, Kyoko, and even the kaiju drawn into the mix, their various motives intertwine as a desperate crisis closes in on the Mini Kaiju!

After his home planet, H12, is destroyed by space kaiju, a lone alien named Teo escapes to Earth and lives as a veterinary student. When the same threat arrives, his will to protect transforms him into a giant hero—Ultraman.