In the world of Sarai, mass flooding has wiped out Japan. Due to an abnormal genetic trait people in this land rarely live past 16, and when they do, they become hideous monsters. Order in this world is almost non-existant. One of the last forms of protection left are the warrior maids, bodyguards for hire. They will do literally anything for the client, and are hired as protective slaves. Sarai Kannagi and her partner, Flicker, are two of these. In their adventures they fight humans-transformed-into-giant-rock monsters, hairy arctic people, and other abominations of the future barren world.

(Source: Anime News Network)