One day, Subaru, a young stargazer, discovers an indoor garden instead of her usual observation room at school, leaving her in shock. She meets Minato, an odd boy who insists she leaves immediately. To add to the strange events, a blob-like creature steals Subaru's compass and leads her to a club room filled with girls dressed as witches - including her friend Aoi, who objects to Subaru joining their search for the club's mystery. Subaru receives magical powers and a staff shaped like a car from the club president, who turns out to be the blob-like creature. Together with Itsuki, Hikaru, and Nanako, they search for engine fragments of a spaceship belonging to the Pleiadians. However, they aren't the only ones seeking it.