The Millennians, the same aliens who brought the asteroid to Earth have arrived on the planet, and unleashed a roster of monsters to attack cities and claim world domination, they even go so far as using Godzilla II under their control, leading them to the destruction of the world. But Miki Saegusa comes to his aid using her telekinetic powers to help him turn his back on the aliens. The rest of the movie sees Godzilla II along with his friends from Monster Island beat up all the aliens' monsters all the way up to the four horsemen of the apocalypse, Gigan, Bagan, and Monster X (Emperor Ghidorah).
