Mobile Suit Gundam: The Origin - Advent of the Red Comet.

This is the story of how Char Aznable, the Red Comet, came to be. Zeon Zum Deikun suddenly dies, in the middle of declaring the Autonomous Republic of Munzo’s independence, and the republic falls into turmoil. His children, Casval and Artesia, escape to Earth while the House of Zabi rises to power. Living in secret, the siblings must find their place in a world preparing for war.