The spaceship AAB-Gamma is dispatched from FAFC headquarters in Japan to make a landing on the planet Mars and investigate reports of UFOs in the area. As they near the red planet, they encounter a mysterious UFO that coats the ship's hull with unusual spores. Taking one of the specimens back to earth, it soon develops and grows into a giant chicken-lizard-alien monster that tramples Japan.

When heads of state gather at the G8 summit in Japan, Guilala -- the intergalactic monster that had been banished from the earth in The X from Outer Space -- returns to ravage the Japanese countryside and threaten the world leaders. Military strikes prove futile against the beast, but a reporter learns that one rural community possesses a strange ritual that might influence the creature. Minoru Kawasaki directs this campy satire.