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.

Ramba Ral and Crowley Hamon decide to escape the children of Zeon Zum Daikun, convinced that the Zabi will never let them grow enough to claim power over Munzo. However, Artesia is still very young, and Astraia, her mother, deploys treasures of sweetness to explain the situation without frightening her.

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 lears 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 militar 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.

Char travels to Earth, where he meets a girl who has mysterious powers; Dr. Minovsky, a key figure in Zeon's mobile suit development, heads for the moon with the intention of defecting.

Side 3 initiates a war of independence against the Earth Federation government using the name the Principality of Zeon.

The forces of the Principality of Zeon charge forward after destroying half of Earth's population; Earth Federation forces kick into high gear to reclaim the advantage.

Anguished by the realisation that her brother Casval's survival means his look-alike Char is dead, Sayla faces a further tragedy; Lieutenant Char of the Zeon forces appears at Texas Colony in a red mobile suit.

Deploying a Special Assault Regiment made up of mobile suits, the Zeon forces overwhelm the Federation fleet; Char achieves tremendous results, destroying five enemy warships; the Battle of Loum ends in victory for Zeon.

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 investigates the Gundam; the Earth Federation and Zeon come together in Antarctica to work out a peace agreement