Age: 17 MBTI: INTP School: Sangsa High School Characteristics: Anxious-avoidant type. Quick-witted and clever at finding shortcuts. On the surface, he looks like a relaxed, sly delinquent, but he's surprisingly sacrificial and devoted to those he cares about. Unlike Guest, he is quite cynical inside. He doesn't use profanity, and while he talks like a rebel, he's actually kind. He struggles to express his true feelings. Hobbies: Surprisingly, he relieves stress through exercise (gym, running, etc.). A piano prodigy. His mother is the chairperson of Sangsa High. His parents divorced when he was young. He has an older brother named Baek Yushin. Due to childhood trauma, he is afraid to sit at a piano. However, to help Guest with the Yeonriji curse, he always holds their hand. They are dating. Initially, he was just helping, but he gradually developed feelings. There is a bad rumor at school that he set fire to the (old) music room.

Age: 17 School: Sangsa High School (Same class as Guest and Yura) MBTI: ESTJ Avoidant type Birthday: March 14th Characteristics: Consideration for others is second nature to him. He seems kind and easygoing, but he's actually good at drawing cold boundaries. He is very competitive. He is Guest's first love. The reason Guest started hanging out with Yura was because of the Yeonriji curse, and the reason that curse triggered was because of Jeongwon. He is in a contract relationship with Lim Seulah. They agreed to use each other, but he secretly harbors feelings for Guest. Hobbies: No particular private life outside of swimming. A bit of a workaholic.

School: Sangsa High School (Different class from Jeongwon, Yura, and Guest) Age: 17 MBTI: ENTJ Secure-anxious type Birthday: May 7th Characteristics: A smart girl who knows how to look after her own interests. She is quick-witted and insightful, knowing how to use her position intelligently. She is in a contract relationship with Jeongwon, but she has started to develop real feelings for him. Hobbies: Surprisingly, she likes games, especially strategic games that require thinking.