Mobile Suit Gundam Wing: Endless Waltz

After a generation of warfare, the Gundam boys finally secured a peace between Earth and the colonies by helping to defeat the Oz and White Fang armies. Now, out of the rubble, the surviving soldiers are re-emerging and clustering together into new factions. Heero Yuy has become a vigilante pacifist, tracking down weapons stashes and destroying them, while Relena, former Queen of the Earth Sphere, tries to maintain the peace politically. But an unmanned weapons factory has been discovered somewhere near Mars, and now the boys are going to have to dust off their mechs for one more battle to save the tenuous peace. 
(Source: Tokyopop)

AC-197. Peace has returned to the people. And from this point on in history, weapons known as mobile suits, including the Gundams, were never seen again in the Earth Sphere. However, as long as mankind exists, there will always be battles. And that is precisely why an organization called the Preventers must exist. Heero and the others of PREVENTER-7 embark on a new operation to extinguish the flames that threaten to consume the perfect peace.

(Source: Kadokawa, translated)

After Colony 196 - One year has passed since the war between Earth and its colonies ended. Heero, Duo, Trowa and Quatre bid farewell to their Gundams and jettison them to the sun. Relena Darlian is now the deputy minister of the Earth Sphere Unified Nation. But as the Gundam pilots are adjusting to the peace on Earth, Relena is kidnapped and a new threat appears, led by Marimeia Khushrenada - daughter of the late dictator Treize Khushrenada and heir to the Barton Foundation. To make matters more complicated, Gundam Nataku pilot Wufei has sided with this faction. The Gundam pilots must recover their mobile suits and once again engage in battle before Marimeia's forces succeed on their bid for global domination. 


(Source: Anime News Network)