Ryu Da-in

A mother with a heart of gold navigates the cutthroat world of private education when her daughter tries to join a celebrity math instructor's class.

Every last Thursday of the month at an all-girls high school, the students of Class 2–5 cast their votes in a popularity poll. The results classify them into Grades A, B, C, D, and F. If they fall into Grade F, they become legitimate victims of school violence.