Year Seven of the Kowa Period, in the former Hokkaido Block, live brothers known as the Nameless Mercenaries. The Emperor, Callis al Britannia, tries to plunge the world into chaos with the help of his servant, Norland, and his Einberg Knights. Rozé and Ash take action from the Northern lands.
In 1972, the Apollo 17 mission discovered a hypergate to Mars on the surface of the moon. Soon a war breaks out between Earth and Mars, and Martian soldiers begin to descend from the sky, riding steel giants, intent on exterminating humanity.
Ensign Shiro Amada is transferred to Southeast Asia to take command of the 08th MS Team. In their first guerilla operation, Shiro's team is tasked with distracting the Zeon forces while Federation ground troops locate a mysterious new Zeon weapon.
Cosmic Era 71. Mankind has developed into two subspecies: Naturals, who reside on Earth, and Coordinators, genetically enhanced humans capable of withstanding the rigors of space who inhabit orbital colonies known as PLANTs. The story revolves around a young Coordinator named Kira Yamato, who becomes involved in the war between the two races after a neutral space colony secretly developing mobile suits for the Earth Alliance is attacked by the PLANTs' military force, ZAFT.