A school festival on the space colony Frontier IV breaks apart when the Crossbone Vanguard opens fire, and Seabook Arno scrambles for cover with his classmates as the Earth Federation loses its grip on the habitat. Meitzer Ronah founded the militia on a creed he calls Cosmo Aristocratism and means to unseat the Federation, while Seabook's way out carries him toward a mobile suit called the Gundam F91. Yoshiyuki Tomino writes and Junji Oono draws this manga, which reopens the U.C. 0123 war of Mobile Suit Gundam F91.