After moving to his late mother's hometown, Kouichi starts attending North Yomiyama Junior High School. However, he senses a weird atmosphere in class 3-3 - as if everyone is afraid of something. Meanwhile, his mysterious classmate, Misaki Mei, is treated as if she doesn't exist... On the second day of the first semester midterm exams, a family emergency causes 3-3's class president, Sakuragi Yukari, to rush out of the classroom. But she trips on the stairs...