The Earth must protect itself from alien invaders.This is a task handled by the Science Special Search Party. However, they are not alone in this endeavor.After crashing his ship on Earth while in pursuit of the evil alien Bemular, the super-being Ultraman is there to provide assistance when the aliens are too much for humanity to manage by themselves.

Ultraman is the ultimate warrior and protector of peace in the entire universe. For eons he's been fighting an intergalactic battle against Gudis, an evil virus that attempts to wipe out all competing life forms. Now the Gudis virus has infected Earth, producing a horrifying group of giant mutant monsters to carry out its goal of the complete obliteration of every organism on Planet Earth. Ultraman now must battle Gudis and his mutant monsters on Earth. But the Earth's polluted atmosphere poses a threat to Ultraman and he has to become part of a human's molecular structure. Jack Shindo has the ability to transform into Ultraman by using his Delta Plasma Pendant (which holds Ultraman within his molecular profile) to transfer his molecules into that of the interstellar hero.

But Ultraman can battle on Earth for only three minutes before he must return to human form.