Akira Toudou is a high schooler in northern Okinawa who lives quietly with his mother, who runs a cafe, and his older sister Haruka. The family keeps a secret: Haruka has inherited a mysterious power from their father and hides it from everyone. Akira received nothing and feels inferior because of it. When strange events start happening around the world and an unknown enemy closes in on Akira and his friends, the fate of the universe is at stake. The brother with nothing and the sister with everything must discover what they can do together in this action mecha story.