Eight years after the One Year War, the Earth Federation creates an elite force called the Titans to hunt Zeon remnants. When Titans proves to be no better than Zeon, the Anti Earth Union Group (AEUG) is formed to restore peace in space.

Nanako and her childhood friend Tomoko enter a special all-girl high school where students are rich upper class. The series is about events that take place during her schooldays, which she chronicles in letters she sends to her brother.

Following the decisive battle against the Titans, AEUG's Argama crew (along with a new bunch of kids), has little time to regroup as a new threat looms in the horizon: Haman's Neo Zeon!