KUMASHIRO Ai (14-years-old) is an energetic and friendly middle schooler. Her childhood friend, Kotarou, is a goofy, 15-years-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!?