In the distant future, Mankind has colonized space with clusters of space colonies at each of the five Earth-Moon Lagrange points, and down on the Earth, the nations have united as the United Earth Sphere Alliance. However, the Alliance oppresses the colonies with its military power. The colonies desire a peaceful resolution to the situation, joining together in a movement headed by the pacifist Heero Yuy. Yuy is shot dead by an assassin, forcing the colonies to search for other paths to peace. The assassination also prompts five disaffected scientists from the Organization of the Zodiac, much more commonly referred to as OZ, to turn rogue after the completion of the mobile suit prototype Tallgeese. It is the year After Colony 195, and war between the Space Colonies and Earth has begun. To give the colonies an edge, they send 5 young soldiers, trained to perfection, to earth in the most powerful of Mobile Suit-Gundams to destroy OZ. With their arrival, the tide of the war changes as they battle against the Earth forces and the Colonies of their origin.