Even in her second year of high school, Okudera Nodoka remains a loner that is, until she made a friend named Segawa. She found her heart racing from his large arms and the kind eyes hidden behind his glasses and now she can't hold back from wanting to get along better with him.

However, something doesn't sit right with her. Segawa-kun only appears during their lunch break, and at school, he has an "older brother" who looks exactly like him... Just which of "you" is the person that I know?