Galaxy Angel II: Mugen Kairou no Kagi is the second Galaxy Angel II game, and it is the sequel to Zettai Ryōiki no Tobira. Two new members join the Rune Angel Troupe, Natsume Izayoi and Roselle Mateus. Taking place 6 months after the events of Verel's Insurrection, the crew find themselves In the midst of a reassignment upheaval. The Luxiole now act under the authority of the UPW and come into conflict against the Arms Alliance, a union of three planets that are outside of the Seldar Alliance. The Three Marquis challenge the Luxiole to their "game" while a bigger threat looms over them.