Kim Yerim, the daughter of a laundromaut owner, gets a full scholarship to the popular and expensive school, SM High. There she meets the famous V4 clique and starts to question herself and change their lives along with hers. 

Park Sooyoung believed that there is only one girl in the world and that girl is no other than her childhood best friend, Kang Seulgi. One day she crosses paths with the human embodiment of Satan, Kim Yerim, and this girl might just change what she believes in.

  yeri thought joy would always be by her side