Heliopolis and the Theft That Starts the War
Earth Alliance Hardware, Stolen By the People It Was Built to Fight
The Heliopolis Heist
The Earth Alliance secretly develops five prototype Gundams on the neutral colony Heliopolis, hoping neutrality will keep them safe from ZAFT eyes. A ZAFT infiltration team steals four of the five. Kira, a civilian student on the colony with no military background at all, ends up piloting the fifth purely because he's the only one standing near it when everything falls apart.
GAT-X105 Strike
Piloted by Kira Yamato
The one Gundam that doesn't get stolen, and the reason the entire series has a protagonist. Strike is built around a modular Striker Pack system, different weapon loadouts physically docked onto the suit depending on mission needs, making it less a single fixed machine than a chassis Kira has to keep re-equipping mid-war.
The Four Stolen Gundams: Duel, Buster, Blitz, Aegis
Piloted by ZAFT's Le Creuset team
The four Gundams ZAFT successfully makes off with from Heliopolis, each given to a different member of Rau Le Creuset's team, Athrun Zala among them, piloting the Aegis. THE BREAKDOWN: the fact that Kira's closest childhood friend ends up on the opposite side of this exact heist isn't coincidence dressed as drama, it's the entire premise of the show compressed into one opening arc.
ZGMF-X10A Freedom
Kira Yamato's late-series upgrade
Kira's successor machine once Strike stops being enough for the war he's actually fighting. A demonstration bout between Strike and Freedom is referenced in official material as proof there's barely any raw output difference between the two, meaning Freedom's real advantage isn't brute power, it's what a more advanced, purpose-built frame lets a pilot actually do with that power.
ZGMF-X09A Justice
Athrun Zala's late-series upgrade
Athrun's counterpart machine to Kira's Freedom, arriving at the same point in the story for the same reason, an escalating war that's outgrown the hardware both pilots started with. Director Mitsuo Fukuda has said the name was chosen specifically as a partner concept to "Freedom," which tracks: this is a show that keeps pairing its two central pilots even in how their machines get named.