A 'top-it girl' from a prestigious high school in Gangnam has disappeared. This emotional and mysterious high school drama begins the story when she returns losing her memory. Hiding her real self, she struggles to survive as an it girl at the school and because of her, hidden secrets and desires start to come up to the surface. Then, their own league and regulations go awry in their exclusive world. Will she be able to break the old rules and make their friends change?