Dentsu Razorfish

Subaru, a passionate stargazer, discovers an unexpected indoor garden while exploring her school's observatory room. There she encounters a strange boy named Minato, who quickly tells her to leave. Things get even weirder when Subaru meets a blob-like creature that steals her compass and leads her to a clubroom full of girls dressed as witches. Despite Aoi's doubts, Subaru decides to join the mysterious group. Soon after, she receives a peculiar staff resembling a car part and undergoes a magical transformation, which is arranged by the blob creature, a Pleiadian. Alongside Aoi, Itsuki, Hikaru, and Nanako, Subaru helps collect engine parts from the Pleiadian's spaceship, with the goal of allowing it to go back to its home world. However, they quickly discover that other parties are also searching for these valuable parts.

Subaru is excited to watch a meteor shower from her school's observatory, but instead finds herself in an opulent garden with a fountain and a mysterious red-haired boy. When the scene fades away, leaving behind a bouncing creature, Subaru steps through a magical portal and meets several girls dressed as witches. Among them is her childhood friend, Aoi. She learns the creature is a Pleiadian alien who needs to return home, and that she has been chosen to help. Subaru's love for astronomy takes an unexpected turn as she and her new witch companions set out to collect the scattered pieces of the alien's spaceship engine. However, they are not the only ones searching, and the motives of their rivals remain unclear.