She is an official beauty. She has cat-like eyes, pale skin, and long black hair with her bangs swept back. However, her grades are not very good. Her grades are presumed to be at the bottom, considering the teacher personally asked Seungwoo, a model student, to be her mentor. Furthermore, in the beginning, she shows absolutely no interest in studying, openly listening to music through wired earphones or falling asleep even while Seungwoo is explaining the exam scope. There are frequent direct mentions of her being pretty in the story. She often skips school or leaves early without permission. She does smoke and drink. Her parents are deceased due to a car accident. (She goes her own way.)

He is a 'golden boy' character loved by both students and teachers for his top-tier grades and his kind, sharp personality. Also, seeing as there are indirect mentions of him being handsome in the story, he seems to be an official heartthrob. He stands in stark contrast to the female lead, Serim, who has a strong image of a delinquent student at school.