So-Ah works as a teacher at a local school. She was curious about Boo Young-Suk, a student with a sinister aura who is always present on the attendance list but no one calls him by name. The more she tries to get Boo Young-Suk back to school, strange things begin to happen at school.
Kim So-hye , Jung Yoon-suk , Lee Gyu-hyeon , Yoo Na-gyeol , Karin , Yeonge
