Fujinami Kou is a high school second-year who had lost his boyfriend, an upperclassman schoolmate, to a car accident an year previously. On the anniversary of Misumi senpai's death, Kou is dispirited and contemplating skipping school. Kakitsubata Saki, a first-year, sees him and offers help, assuming that he's ill. As Kou startles at the sight of Saki's face and mentions that he resembles "the person I used to go out with", the younger boy is instantly intrigued and resolves to discover his sorrowful, introverted upperclassman's secret.