A beautiful girl falls out of the sky and lands in Yusuke's lap - literally. This mysterious girl suffers from amnesia and remembers nothing except her name, Rouge. Ever the gentleman, Yusuke offers her a place to stay until she recovers her memory. Then, two noble women, her sisters Kaige and Meige, appear in royal armour claiming Rouge is from the royal family of a mysterious magical world! Will Yusuke survive when the royal family's powerful enemies stage an assault?