The Equal Environment of Earth Union, a radical organization determined to equalize the balance of power between nations, steals a time machine from the Earth Union, and uses it to travel back to 1992, where they initiate a plan to weaken Japan before it becomes a corrupt superpower in 2204. However, this fails after one of the Futurians, Emmy Kano and her android, M11, foil their plans in battle.
The body of the three-headed monster King Ghidorah is discovered laying on the bottom of the Okhostk Sea off the coast of Russia and Hokkaido. The body is recovered and improved with mechanical components, including a new middle head and armor over it's body and damaged wings. The cyborg, dubbed Mecha-King Ghidorah, is then sent to the year 1992 to battle Godzilla.