Mobile Suit Gundam Wing: Battlefield of Pacifists

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)

After the events of Gundam Wing, peace still does not come easily. Small rebel factions slowly gain influence and power, and those that were wronged during the war creep out from the woodworks. Relena, a symbol of peace and a primary political figure in the post-war rebuilding efforts, is kidnapped. The five pilots must once again come together in order to protect their fragile peace while simultaneously wrestling with their own morals and motivations.

Just when he thought life was returning to normal, Heero Yuy receives a cryptic message from a person claiming to have stolen the Wing Zero and requesting a rendezvous at a remote space station. There he finds the station deserted except for his fellow Gundam pilots all of whom have received similar messages. But only a handful of people are capable of piloting the Wing Zero... As tension and distrust grows, Heero is pitted against his comrades with mind control, assassination, and a loaded gun thrown into the standoff.