A ruined world where mechanical bodies known as "Avatars" are becoming widespread. Ao, a girl living in the lower levels of the city, barely scrapes by each day working as an Avatar mechanic. One day, in a back alley, she finds an Avatar girl named Ariadne in a battered state. Unable to just leave her be, Ao repairs her, but as soon as Ariadne wakes up, she kisses Ao and says, "Let's get married..." Girls living at…