The mystery hook in episode one plants a question that rewatches will answer completely differently. The middle sags like it's just another school romance, but those three final episodes recontextualize everything that came before, turning what felt like filler into the actual story. By the time the time travel reveal lands, you're already emotionally invested in these specific people trying to save a specific autumn, and that's what makes it hit.

Sou Akiyama's Astronomy Club, packed with some of the best-known students on campus, gets ready for Uchihama Academy's last General Club Festival in the old building before it closes for good. Just ahead of the October 1 event, the student executive committee asks the club to settle the nerves of a student body rattled by strange events in the old building: ghost sightings, accidents and a sleeping sickness. Club member Kaori Sasaki confesses to Sou and dies in a road accident that same evening, yet she turns up at school the next day as if nothing had happened. Soon Sou comes across an unconscious girl, and a quiet late transfer student named Yui Furukawa enters his life. The club moves from ghosts to feuds between student clubs while digging into how the new student came to appear. The show blends drama, romance, science fiction and the supernatural.