Universal Century 0068. Casval and Artesia are the orphaned children of Deikun, who preached the reformation of humanity through advancement into outer space and independence from the Earth Federation government.

With Deikun's death, conflict intensifies between the Zabi and Ral families. To escape the political strife, Deikun's orphaned children Casval and Artesia say farewell to their mother and depart for Earth with Jimba Ral.

Universal Century 0071. Changing their names to Édouard and Sayla, Casval and Artesia have begun new lives on Earth as the children of Teabolo Mass, but they are attacked by assassins dispatched by Kycilia.

Sayla and Édouard are grief-stricken by the death of their imprisoned mother, and Édouard swears revenge upon the Zabis. He learns that the Aznable family's son Char is entering the Zeon military academy, and devises a plan.

At Side 3, Dozle's development of humanoid mobile weapons makes dramatic progress with the assistance of Doctor Minovsky. Meanwhile, at the military academy, Char befriends Garma and urges him to attack the Federation Forces barracks.

The military academy students launch an armed uprising under Garma's command and attack the Federation Forces barracks. Lino, who knows Char's true identity, is killed in the fighting thanks to Char's behind-the-scenes maneuvering.

The military academy students launch an armed uprising under Garma's command and attack the Federation Forces barracks. Lino, who knows Char's true identity, is killed in the fighting thanks to Char's behind-the-scenes maneuvering.

Universal Century 0079. Side 3, the space city furthest from the Earth, launches a war of independence against the Earth Federation government under the name of the Principality of Zeon.

The Principality of Zeon forces advance after wiping out half of Earth's population by carrying out a colony drop. In response, the Earth Federation Forces mobilize their overwhelming fighting strength to regain the advantage.

Anguished by the realization that her brother Casval's survival means his lookalike Char is dead, Sayla now faces a further tragedy. Meanwhile, Lieutenant Char of the Zeon forces appears at Texas Colony in a red mobile suit.

Char becomes a hero of Zeon thanks to his exploits in the Battle of Loum, earning a promotion to Lieutenant Commander and the nickname "Red Comet."

Amuro tries to discover the secret of the "Gundam." Meanwhile, high officials of the Earth Federation and Zeon forces begin peace talks in Antarctica.