A group of scientists are on the tropical island of Solgel in the Pacific to conduct weather control experiments. Just before they start, they find giant prey prayers that are 25 feet high and called Kamakaras. They decide to continue with the experiments, but a malfunction in one of the devices and, as a result, a radioactive storm that raises the temperature to two hundred degrees. Due to the storm, the praying mantis become even bigger and become 100 feet high. The Mantises then make their way to a huge hill where they uncover a giant egg containing a young Godzilla, later called Minilla. Finally, Godzilla appears and rescues his offspring. The remainder of the film shows Godzilla, who takes care of his little son and teaches him the skills that will eventually help him become the new "king of monsters", as well as the fight against the Kamakaras and a giant spider called Kumoga.