Wataru Hoshino's quiet life in a dormitory shared with four girls and their teacher takes a chaotic turn when he finds a sleeping stranger in his room one morning. After a punch to the face and a dramatic window exit, that same girl, Rinna Sawaki, turns up as a transfer student at his school and his new dormmate. Their island's major company, Temizugawa Heavy Industry, is closing its aviation branch, and the families tied to it must evacuate within a year, so the four girls will soon be gone. With an expiration date hanging over their time together, Rinna keeps everyone at arm's length, convinced that closeness will only hurt more when separation comes. Wataru disagrees, and over the course of that year he tries to change her mind. The result is a drama about attachment and whether it is better to avoid connection or embrace the time you have.