The film's protagonist, Seabook Arno is the son of mobile suit and weapons designers Leslie and Monica Arno. Unaware of the full extent of his parents' work, Seabook ends up Falling into the Cockpit of their Super Prototype, the Gundam F91 when the Crossbone Vanguard launches an attack on his home colony.
Ace Pilot: Reaches this status by his second battle.
The Everyman: In a sharp contrast to previous protagonists, and his own parents, Seabook doesn't really have any distinguishing characteristics prior to his fateful run in with the titular mobile suit.
Falling into the Cockpit: Downplayed. Seabook discovers the F91 by accident, but volunteers to fly it, since his mother was the one who designed it in the first place.
Lightning Bruiser: The F91, as is typical for the protagonist mobile suits. It's faster, harder hitting, and better armoured than anything the Federation or Cosmo Babylonia has at their disposal.
Nice Guy: Seabook is a fairly pleasant, average kid prior to the events of the film.
Official Couple: With Cecily, who was his girlfriend before the film began.
Took a Level in Badass: Takes a massive one over the course of the film going from an average student to a battletested veteran pilot.
Seabook's girlfriend, Cecily Fairchild is the daughter of Carozzo Ronah and the granddaughter of Metzer Ronah, both of whom want her to act as the figurehead for Cosmo Babylonia's conquest of the Earth Sphere. Kidnapped and forced into the role, Cecily keeps her own council, and eventually turns against them.
Voice Actors: Teppei Takasugi (Japanese), Simon Isaacson (English)
The leader of the aristocratic Cosmo Babylonia, Meitzer is Cecily's grandfather and Carozzo's father-in-law, and the man who is most to blame for the outbreak of conflict between the EF and the Vanguard. Believing the world is going to run itself into the ground, he aims to save it by imposing his own rule on the Earth Sphere.
Voice Actors: Masaki Maeda (Japanese), Tom Wyner (English)
The son-in-law of Meitzer Ronah, Carozzo is the field leader of the Crossbone Vanguard, and a massively augmented Cyber-Newtype as well. Incapable of removing his mask, Carozzo is able to directly interface with machinery at the cost of his interpersonal skills and his basic humanity, with his wife, daughter, and father-in-law all distrusting and fearing him. He pilots the Rafflesia mobile armour.
Archnemesis Dad: To his daughter, Cecily, whom he eventually tries to kill.
Batman Can Breathe in Space: Suffers no ill effects when he emerges from the Rafflesia into hard vacuum. It could be that his mask contains an air supply, or that his Cyber-Newtype modifications included some sort of alternative form of respiration, but since neither is specified, this trope is still very much in effect.
Carozzo's son and Cecily's half-brother, Dorel Ronah was adopted into the larger family by Meitzer when Carozzo married Cecily's mother. Arrogant and determined to prove himself, Dorel acts as one of Meitzer and Carozzo's mobile suit pilots, spearheading the initial attack on the colonies. He has a rivalry with Zabine Chereaux.