A mysterious benefactor has provided the three superpower blocs with a new weapon against the Gundams. Quickly establishing a military alliance, the superpowers organize an elite fighting force under the aegis of the United Nations.

The United Nations forces have deployed their new weapon, a mobile suit model known as the GN-X which is powered by a pseudo solar reactor. While Sergei Smirnov and Soma Peries lead a GN-X team in pursuit of the Gundam Thrones.