Fifteen years have passed since the catastrophe of the hypergate collapsing on the moon’s surface, known as the Heavens’ Fall. The war between the citizens of Earth (Terrans) and the Vers Empire of Mars is now at a ceasefire. They are far from any agreement over which civilization is the rightful heir to the power of the ALDNOAH, an ancient Martian technology discovered not long after the celestial hypergate. Princess Asseylum Vers Allusia descended upon earth as an ambassador to bring reconciliation, but some were not willing to compromise. Inaho Kaizuka is a Terran high school student. Slaine Troyard swears his allegiance to Vers. As citizens of both societies witness the assassination of Asseylum, the fate of these young men and a strange woman cross.