Unable to sleep at night, Ganta Nakami is cranky in class and unpopular with his classmates. He discovers that the school observatory, once used by the now-defunct astronomy club, may be the perfect place for a nap--but he's not alone. Fellow insomniac Isaki Magari is willing to share the observatory with Nakami, and a friendship between the two begins as they bond over the most unlikely things.

Following the disappointment of the canceled meteor shower viewing party, Nakami and Isaki switch their focus to the photography contest and head out on an astronomy club trip with Isaki's sister, Haya. Isaki and Nakami come back from a night of snapping photos to find Haya leaving. Now they're all alone together in the countryside. How will this change their relationship?