Yuzu is an honor student who attends a school in Tokyo and is a serious student with a strong sense of justice. - Her family is wealthy and she is able to study well, and she plans to attend a famous university after graduation. - On the other hand, classmates Kawagoe and Meguro used to be honor students, but they stumbled in their studies and are now inferior students with bad behavior. - One day, Yuzu comes across Kawagoe having a cutthroat. - Yuzu warns Kawagoe about his behavior and looks at him with disdain. - Kawagoe, angered by Yuzu's attitude, secretly films Yuzu defecating and threatens her by using it as a joke. - And then during the summer vacation...I called her to a classroom where there were no students and did my best...