In Houkago no Pleiades, the sky is the limit. Subaru is on her way to her school's observation room with a telescope in hand, hoping to get a glimpse of the meteor shower that night. What she doesn't anticipate is to find a gorgeous garden with a spectacular fountain and a mystery young lad with long red hair inside the observatory door, rather than the starry heavens. But the garden vanished quickly, like if Subaru was hallucinating. All that remains of that magnificent sight is a strange, bouncing blob monster that takes her to another magical door, which is populated by other females dressed as magical witches. Subaru is bombarded with revelations one after the other: one of the girls in the room is her childhood friend Aoi, the little blob is actually an alien of a species called the Pleiadians trying to return home, and Subaru has been selected by him to become the newest member of their group!