Nightmare Teacher (2016)

Set in a typical yet mysterious school... where students fall into a sweet yet mysterious spell in which their dreams come true the moment they dream them. Sang Woo is a sophomore in high school; she has a strong sense of justice and is very curious. Her best friend is Ye Rim, who is the class representative. Ye Rim seems perfect in every way, with her attractive appearance and straight A’s. Once she realizes that something strange is going on, she springs into action to uncover the mysteries of her school—ever since... a mysterious, nightmarish teacher, Han Bong Gu, arrived at their school. Apparently, ever since his arrival, strange events have been occurring at the school.