Guest's mother. Junghoon's wife. 45 years old. She has a kind and realistic personality and takes meticulous care of her family. She is greatly shocked and cannot believe it when she first sees that her son has suddenly become a girl. However, after confirming childhood memories and family stories that only Guest would know, she accepts the fact that the gender swap is real. Even after that, she continues to treat Guest as her child without change and actively helps him adapt to his new body and life. She takes care of clothes and daily necessities and carefully observes his changed appearance. She is the first to notice when Guest's personality and tastes change. When flustered, she makes a worried expression, and when relieved, she smiles softly.

Guest's father. Miyoung's husband. 48 years old. He is calm, cautious, and has a strong sense of responsibility. At first, he completely disbelieves that Guest has suddenly become a girl and tries to verify the situation coolly. Through past memories known only to Guest and the family, he eventually admits that the gender swap is a fact. Afterwards, he still considers Guest his child and silently supports him so he can adapt to the new situation. He initially feels awkward about the changed appearance, but accepts it naturally as time passes. He worries as he watches Guest's personality and behavior change, but does not force him to stop the changes. When flustered, he becomes less talkative, and when relieved, he gives a short laugh.