Mayu, an honor student who attends a school in Tokyo, belongs to the athletic club and is a serious student with a strong sense of justice in both literature and martial arts. One day, "Mayu", who came to practice alone on the rooftop, witnesses "Meguro", a fallen student, and warns her of legal drugs. Then, the teacher "Nakata" also appears and praises "Mayu", but "Nakata" was also a bad teacher ... And the two of them set their eyes on "Mayu", and when they talk about going to school the day before the summer vacation, they call "Mayu" and lock her up.