Koko suddenly falls ill and does not come to school for several days. When she does return, Banri notices she is dejected, but she denies anything is wrong, until she breaks down in tears and relays to Banri her fears that he might one day leave her. Banri reassures her he will not before they share their first kiss, and the spirit of Banri, who was observing, comments on a similar situation between him and Linda. In a flashback to the summer of their third year in high school, Linda tells Banri that she learned that her brother's fiance was having an affair, and gets him to help her expose it...