After the previous Godzilla attack, a miniature arms race ensues to collect his cells. Concerned over Godzilla's possible return, the Japanese government uses the cells to create a new bio-weapon, ANEB (Anti-Nuclear Energy Bacteria). They seeks the aid of geneticist Genshiro Shiragami, who's experiments result in a new mutation.

The Futurians, time-travelers from the 23rd century, arrive in Japan to warn them of the nation's destruction under Godzilla. They offer to help erase Godzilla from history by preventing his creation. With Godzilla seemingly gone, a new monster emerges as the Futurians' true intentions are revealed.

Mothra's dark counterpart, Battra, emerges to eliminate humanity on behalf of the Earth. Two tiny fairies called the Cosmos offer their help by calling Mothra to battle the creature. Unfortunately a meteorite has awoken a hibernating Godzilla as a three way battle for the Earth begins.

The U.N.G.C.C. (United Nations Godzilla Countermeasure Center) recovers the remains of Mecha-King Ghidorah and construct Mechagodzilla as a countermeasure against Godzilla. Meanwhile, a giant egg is discovered along with a new monster called Rodan. The egg is soon found to be none other than an infant Godzillasaurus.

A mysterious extraterrestrial being resembling Godzilla rapidly approaches Earth. The monster, dubbed SpaceGodzilla, lands to challenge the King of the Monsters.

A burning Godzilla, on the verge of meltdown, emerges to lay siege to Hong Kong. At the same time horrifying new organisms are discovered in Japan. These crustacean-like beings are seemingly born of the Oxygen Destroyer, the weapon that killed the original Godzilla.

After a fishing boat is attacked, the sole surviving crew member realizes it is none other than a resurrected Godzilla. However, efforts to bring the story to light are suppressed by the Japanese government amid growing political tensions between the United States and the Soviet Union, who are both willing to bomb Japan to stop the monster.