A week before the graduation ceremony, Emiru suddenly disappears. Does her sister have something to do with it? Tatsuhiko's alarm bells go off, and he immediately begins his search. While he can't ask Madoka for help, he can rely on his old friend Makiko. In Emiru's room, she finds not only a striking business card from a nightclub but also a piece of paper in a hole in the wall: Emiru's farewell letter.