For a while now, Ganta has had severe trouble falling asleep, and no matter what he does, he ends up exhausted and in a bad mood when he goes to school, where he usually dozes throughout the day.
Despite everything, Ganta is a good student, but he has gained a reputation for being antisocial and constantly in a bad mood.
During the preparations for a school festival, he overhears his classmates talking about a supposed legend, in which a couple of students, part of an astronomy club, lose their lives, causing the school observatory to be closed and converted into a warehouse.
His classmates continue chatting and when they ask Ganta to find more cardboard boxes and stop dozing, he tells them that at least he has already fulfilled his assigned duties.
Reluctantly, Ganta heads to the observatory, and on the way he runs into one of his old friends, to whom he confesses that he has trouble sleeping, headaches and a lot of frustration.
Finally, he decides to look for the cardboard boxes, but notices that the door to the observatory is open and enters to take a look. He discovers a very interesting place, and above all, private enough to take a nap.
But before he does, he finds out that his classmate Isaki is sleeping at the place. Waking up, she is surprised and tries to escape, but once she recognizes Ganta they begin to talk.
Ganta tells Isaki that he locked the door to enter the room, and she tells him that it can only be opened from the outside. Fortunately for both of them, Ganta uses Isaki’s phone to ask for the help of his old friend.
And while they wait, Ganta discovers that Isaki was the one who started the rumors about the place, and that for some reason, she also has a serious problem with insomnia.
Without realizing it, they sit next to each other and while they talk, end up sleeping peacefully.
Isaki asks Ganta not to divulge her secret and gives him the password for the padlock that closes the observatory door.
Days later, because they can’t stay alert, they both end up in the infirmary. And later, Isaki tells Ganta that he needs him at the observatory.
Once there, he notes that Isaki has cleaned up the place and tells him that if they can’t sleep, they should do something fun at night.
Thus, they begin to spend time together, Ganta decides to use a camera that her father gave him while they wander in town.
Subsequently, they decide to request permission to reopen the defunct astronomy club, thus avoiding many problems in the future.
(君は放課後インソムニア)
“Hertz” ~ Homecomings