Woo Seul Ki grew up in a provincial orphanage. She moves to Seoul and enrols at Chaehwa High School, a school for elite pupils – the 1% of South Korea’s top students. Woo Seul Ki does not get on well with the other pupils. A pupil named Yoo Je Yi approaches her and they become friends. Yoo Je Yi is the most powerful pupil in the school. She has a high IQ, comes from a wealthy family and is physically attractive. She has been the envy of everyone since she was born and is well aware of her superiority. She is also shrewd enough to know how to exploit her position. She takes a particular interest in the transfer pupil, Woo Seul Ki. Soon, they develop a dangerous relationship that straddles the line between friendship and obsession.