The stern and inflexible university student, Kwon Jeongha (권정하), intensely dislikes his handsome and popular classmate, Gwak Hyeonwoo (곽현우). The reason? Hyeonwoo played with and then discarded the upperclassman that Jeongha secretly had a crush on. The two fight like cats and dogs, constantly snarling at each other. BUT. One day, a suspicious necklace Jeongha picks up completely flips their relationship upside down. "This might sound absurd, but... I am a 'Devil.'" Hyeonwoo, revealing himself to be a devil, explains that all the magic he had collected in the necklace was absorbed by Jeongha, and if the power isn't returned, Jeongha will die. The only way to return the magic is through skinship (physical contact)! Jeongha reluctantly agrees and begins his forced cohabitation with the devil.