It is A.C. 196—one year after the conflict between Earth and its nearby space colonies ended with the formation of the Earth Sphere Unified Nation. As mankind enters a new era of unity and prosperity, four of the five Gundam pilots decide to follow in society's footsteps and disarm by launching their mobile suits into the sun. However, their plan is unexpectedly suspended when a rebellion erupts with the emergence of Mariemaia Khushrenada—who claims to be the child of fallen dictator Treize and desires to conquer the world in his stead. Deciding that they are the last line of defense for the Earth Sphere, Heero Yuy, Trowa Barton, Duo Maxwell, and Quatre Raberba Winner scramble to retrieve their Gundams and fight to protect the peace the people of the colonies have pursued for so long. Despite their unwavering resolve to complete one final mission, the battle will be challenging: the pilots' former ally Wufei Chang has pledged his allegiance to Mariemaia's cause instead. At the climax of the Eve Wars, on December 24 of the year AC 195, the armies of the World Nation and White Fang met in a ferocious battle. World Nation leader Treize Khushrenada was slain, White Fang leader Zechs Merquise disappeared, and Earth was saved from destruction by the intervention of the five Gundam pilots. Having witnessed the consequences of war and hatred, the people of Earth and the space colonies put aside their differences and together founded a new world government. Under this newly-formed Earth Sphere Unified Nation, a year has passed in peace. The government and the populace have disarmed themselves, and almost every remaining mobile suit has been destroyed. Deciding to follow suit, Gundam pilots Heero Yuy, Duo Maxwell, Trowa Barton, and Quatre Raberba Winner place their mighty mobile suits inside an asteroid and send them on a one-way voyage into the sun. But even as they bid their Gundams farewell, a new conflict is drawing near.