A homeroom teacher of Yosan Private High School has an accident, and thus a substitute comes to fill in. Han Bong-Gu is a mysterious man, and after strange occurrences the class president Ye-Rim tries to get to the bottom of this mystery.
Uhm Ki-joon , Kim So-hyun , Lee Min-hyuk , Seo Shin-ae , Baek Seung-do , Kim Ji-ahn , Jang Kyoung-up , Kim Da-ye , Kwon Young-min , Ji Eun-sung
