A group of scientists are on tropical Solgel Island in the Pacific to conduct weather control experiments. Just before they begin, they find giant preying mantises measuring 25 feet tall called Kamakaras. They decide to go ahead with the experiments, but a malfunction in one of the devices and as a result a radioactive storm that pushes the temperature up to two hundred degrees. The storm also causes the mantises to grow even bigger to 100 feet tall. The mantises then make their way to a huge mound where they uncover a giant egg which contains a young Godzilla, later named Minilla. Eventually, Godzilla shows up and saves his offspring. The rest of the movie features Godzilla taking care of and teaching his young son the skills that will eventually help him to become the new "King of Monsters" as well as fighting the Kamakaras and a giant spider named Kumoga.