Fujinami Kou is a high school second year who has lost his boyfriend, an upperclassman schoolmate, to a car accident in the previous year. On the anniversary of Misumi-senpai's death, Kou is dispirited and contemplating skipping school. Kakitsubata Saki, a first year student, 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.