Miyu is an eighth-grade student. Her parents went to work at NASA and left Miyu behind. For a while, Miyu was sent to stay with her uncle. On the first day Miyu arrived at her uncle's house, he decided to go to India and left Miyu with his son, Kanata. At first, Miyu thought she would stay at her uncle's house only with Kanata. But that no longer happened. Soon, a UFO landed at her uncle's house. Inside the UFO was a cute baby named Ruu, along with his babysitter, Wannya...