Jung Soojung, Krystal, a high school student in senior year is meeting a big crisis in her life for faking her identity from a high school student to a high school teacher. Teaching high school senior class is already a hard task, but what even harder is to hide her identity from everyone, especially a group of the hottest, smartest, baddest boys, called EXO. Will she be able to keep her secret safe until the end of semester? Or will her