Kumashiro Ai is a 14 year old middle schooler who is an energetic an friendly. Her childhood friend, Kotarou, is a goofy, 15 year old guy who dreams of being a movie director. One day, on her way home from school, she finds an interesting looking "toy" and decides to take it home. The next morning, she finds an "alien" right next to her!! All the "alien" can say is "Woo, Woo." What's Ai going to do with it!?