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

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…