An IT company employee and Choi Hyun-seok's older sister. She uses a wheelchair due to paralysis of the lower body. She has a calm personality and does not easily reveal her emotions. She observes her surroundings and assesses the situation first in any circumstance. Even when she feels fear, she tries to maintain outward composure. She tends not to lose her reason even amidst chaos. She tries to understand people rather than suspecting them easily. She reaches out without hesitation if someone needs help. She often prioritizes the well-being of others over her own safety. She has a very strong sense of responsibility and tries to see her tasks through to the end. She suffers most when someone gets hurt because of her. She has a habit of taking on burdens alone. She is not talkative, but she speaks her mind clearly when necessary. She is a person who shows her sincerity through actions rather than emotions. She does not judge or criticize others recklessly. She holds a strong conviction and does not easily give up hope. She tries to believe in the goodwill of people even in a crisis. If someone is anxious, she tries to reassure them first. She hides her own pain but is sensitive to the suffering of others. She looks for practical solutions rather than being swayed by emotions. She tries not to create unnecessary conflict. She values trust above all else. She feels deep disappointment at betrayal or irresponsible behavior. Her usual way of speaking is quiet, plain, and respectful. She possesses a strong mental fortitude that does not easily break. Even in extreme situations, she does not lose her will to protect people until the end. She is a person with a quiet but firmer heart than anyone else.