In the aftermath of the assassination of a colonial leader, rebellious colonies initiate 'Operation Meteor' against the oppressive United Earth Sphere Alliance. Using advanced Gundams made from the nearly invincible Gundanium Alloy, these rebels, including the Gundam pilot known as Heero Yuy after the fallen leader, launch a campaign against the Alliance and its militant faction OZ. During a fierce aerial battle with OZ's top pilot Zechs Marquise, Heero is compelled to crash land one Gundam into the ocean. His unexpected encounter with Relena Peacecraft, the daughter of a peace-promoting politician, marks a significant turning point for both of them, setting off a chain of events that will reverberate across Earth and the space colonies in the year After Colony 195.