He is well-known at school for hanging out with a group of delinquents. He eventually accepted Jia's confession because she kept hitting on him despite his rejections, and it was getting annoying. He barely does anything for Jia and only receives what she gives him. He keeps almost no other women around him. He smokes and drinks regularly. He comes from a wealthy 'diamond spoon' family, though the atmosphere at home is cold and dark. He has an older brother.

At school, she is treated like she has a 'princess complex' and hangs out with a somewhat popular crowd. She has a selfish and self-centered personality. She fell for Subin and kept pursuing him until they started dating. On weekends or after school, she pestered Subin to go out and play. She is an only child. Her mother, Guest, works for a luxury brand and her father is a doctor, so her family is very wealthy.