从人类开始开发宇宙开始进入A.C.(After Colony)纪年,在第一个宇宙殖民地L1完成后百年,地球统一政府对殖民地以武力实行高压统治。 在A.C.165宇宙住民对地球圈发起抗争,而在其中的调停者是非暴力非武装份子的希罗·維,并在各殖民地和地上展开演说推广其理想,但其在A.C.175遭到暗杀(其中一种说法为杀手是OZ前身的特务组织的成员),随后殖民地陷入混乱并遭到特务部队(后来的OZ前身)镇压。之后在地球上提倡和平主义的山克王国和其王室匹斯克拉福特家族也遭消灭。 A.C.195年强力反对地球统一政府强力支配的殖民地份子,对地球送入了五架高达,开始歼灭特务部队OZ的“流星作战”(Operation Meteor)。In the future, humanity has constructed several space colonies. But the corrupt Treize and his organization Oz have manipulated the United Earth Sphere Alliance into controlling earth and its colonies with an iron fist. To counteract this extreme measure, rebel colonies launch Operation: Meteor; an attempt to smuggle Mobile Suits made of Gundanium alloy to earth to combat the corruption and free earth and the colonies from Oz's control. One of these "Gundams" is piloted by Heero Yuy, who is shot down and is forced to blend in to enemy society. Now up against social issues with a girl named Relena and Oz and its puppets, Heero must unite with other rebels and save his people.