Haruyoshi Nakamura

When a space probe crash-lands on a far-flung Pacific atoll, the craft's alien stowaways decide to take over their new world one creature at a time. Soon, the parasitic life forms latch onto three indigenous critters -- a squid, a crab and a snapping turtle -- and transform them into colossal mutant monsters.

A massive underwater volcano erupts and puts a group of investigative scientists in danger. They are rescued by an atomic super submarine named The Alpha under the command of Captain McKenzie. The group is quickly taken to a vast underwater city known as Latitude Zero, a fantastic, Atlantean type utopia, a world beneath the ocean with its own sun. It is soon discovered that Captain McKenzie is at war with the evil Dr. Malic, a cruel scientist who wishes to rule mankind all the while conducting genetic experiments on humans and animals. Malic sends his agents to kidnap Dr. Okada, a human scientist who has created a serum that can immunize exposure to radiation.

Hayata is a member of the Science Patrol, an organization tasked with investigating bizarre anomalies. He is mortally wounded when accidently encountering an alien being from Land of Light, who grants Hayata new life as the two are merged into one. Now, whenever a threat arises that is too great for the Science Patrol to handle, Hayata activates the beta capsule and becomes the hero known as Ultraman.

As supernatural events and monster attacks rock Japan, the military and government look to be overwhelmed. Three intrepid young investigators—two pilots and a reporter—take it upon themselves to study these unexplained phenomena in order to inform and protect the public.