Yoon Na-eun

While preparing to shut down the photo studio business that he has been running, a man hears that someone named Chulsu has died.

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.