Yusuke is an orphaned high school student who just happened to be late for class one day. Little did he know that his tardiness would consequently put him in the right place at the right time...soaking in the middle of a muddy puddle with a girl who quite literally falls right into his lap. Rouge, the mysterious girl who fell from the sky, suffers from amnesia and remembers nothing except her name. Ever the gentleman, Yusuke offers her a place to stay until she recovers her memory. After spending many days playing, shopping, and falling in love, Rouge and Yusuke suddenly encounter two women, Kaige and Meige, who claim to be sisters of Rouge. Now, Rouge and Yusuke are threatened with separation... not only by the sisters who want to take her back home, but also by enemies of the royal family who wish to capture Rouge.