Kidou Senshi Gundam F91

In Universal Century 0123, the Crossbone Vanguard attacks the Frontier colonies and declares the birth of Cosmo Babylonia, an aristocratic order meant to replace the Earth Federation's decaying rule. Teenager Seabook Arno is caught in the invasion while trying to escape with his friends.

Seabook is eventually drawn to the Gundam F91, a mobile suit developed with the involvement of his estranged mother. At the same time, his friend Cecily Fairchild is revealed to be Berah Ronah, heir to the family leading the enemy movement. Their paths place two young people on opposite sides of a new war neither of them chose.