Mayu is an honor student at a school in Tokyo. She is a member of the sports club, excels in both academics and sports, and is a serious student with a strong sense of justice. One day, while practicing alone on the rooftop, Mayu witnesses Meguro, a struggling student, taking legal drugs and warns him. Then, Nakata, a teacher, appears and scolds Mayu, but Nakata is also a bad teacher... The two of them set their sights on Mayu, and on the day before summer vacation, they call her in to talk about her future education, and lock her away...