Unable to sleep at night, Ganta Nakami is cranky in class and unpopular with his classmates. Nakami discovers that the observatory, once used by the defunct astronomy club, may be the perfect place for a nap--but he's not alone. Nakami and his new friend Isaki Magari find comfort in each other while coping with insomnia.

Summer is swiftly approaching for sleepless high schoolers Nakami and Magari. Now members of their school's revived astronomy club, they're busy preparing for their first official club event, a meteor shower watch party! The city's annual fireworks festival is also coming up, and Nakami has promised to go with Magari. Every sleepless night brings the two closer, and their first high school summer promises to strengthen their bond even more...