With a porcelain face that men would (and have) fought over, Yun-Jin is the most desired girl at school. However, her beautiful face comes with a price: All of the girls at school hate her for it. On any given day she can find her locker trashed or her gym outfit torn to pieces. It's not to say that she hasn't done something to deserve it partially, since she also has a terrible attitude under that perfect complexion. Yun-Jin also treats her cousin Miha like a slave, for reasons she will not divulge. It may have to do with an incident in her past concerning Miha. Yun-Jin lived with Miha's family for a while when she was in elementary school after her father's death. Yun-Jin's father had been an alcoholic and had been beating Yun-Jin for a very long time. Due to their pride, Yun-Jin and her mother hid the bruises from the rest of the family. As a result Yun-Jin also suffered seizures whenever faced with violence. Miha's mother spoiled Yun-Jin because of this, and took Yun-Jin's side in any argument, as well as giving away many of Miha's possessions. In one instance Miha's mother gave away her favorite doll, and when Miha tried to reclaim it, Yun-Jin had a seizure, and Miha got scolded. Naturally this was incredibly frustrating for Miha. Yun-Jin also idolized Miha, and would follow her without question. Frustrated, Miha took Yun-Jin back to her old house with the intention of leaving her there, but Yun-Jin had a seizure. Scared, Miha ran off and Yun-Jin wandered the streets for days, eventually ending up in the hospital after an accident. It is unknown whether she still bears a grudge towards Miha because of this, or because of other factors. Yun-Jin does not like Seung-Suh approaching Miha, especially because he keeps telling Yun-Jin to start taking care of herself and to stop relying on Miha. She is willing to do almost anything to keep them apart.