Original Japanese Language w/english subtitles. Uncut Japan Version! A team of scientists stationed on Sollgell Island attempts to perfect a weather control system. Their efforts are hampered by the presence of giant praying mantises and by the arrival of a nosy reporter. The first test of the weather control system goes awry when the remote control for a radioactive balloon is jammed by an unexplained signal coming from the center of the island. The balloon detonates prematurely, creating a radioactive storm that causes the giant mantises to grow to enormous sizes. Investigating the mantises, now called Kamacuras, the scientists find the creatures digging an egg out from under a pile of earth. The egg hatches, revealing a baby Godzilla. The scientists realize that the baby's cries for help were the cause of the interference that ruined their experiment. Soon Godzilla himself arrives on the island, incidentally stomping the scientist's base as he rushes to defend his son. Godzilla kills two Kamacuras during the battle, while one manages to fly away to safety. The baby quickly grows to about half the size of his father, and Godzilla instructs the child on the important monster skills of roaring and using his atomic breath. At first, the baby has difficulty producing anything more than atomic smoke rings, but Godzilla discovers that stressful conditions, such as stomping on the baby's tail, produce a true radioactive blast. Dubbed Minilla, the baby comes to the aid of Riko when she is attacked by a Kamacuras, but inadvertently awakens Kumonga, a giant spider. The spider attacks the caves where the scientists are hiding, and Minilla stumbles into the fray. Kumonga traps Minilla and the final Kamacuras with his webbing, but as Kumonga begins to feed on the deceased Kamacuras, Godzilla arrives to save the day. Godzilla saves his son and they both defeat Kumonga by using their atomic breaths on the giant spider. The scientists finally use their perfected weather altering device on the island and the once tropical island turns into an Arctic wasteland. Godzilla and Minilla begin to hibernate as they wait for the island to become tropical again. The scientists are saved by a submarine.