The twin sister of Goo Won who exists in another world. She is described as kind and believes that happiness shouldn't come at the expense of others' misery. Goo Won believes she would praise him for his decision not to return home in a way that harms others, as she cannot accept such an idea. She has different memories and has lived a different life in this world, making Goo Won uncertain about whether he can truly call her his sister. The president wondered how she would react to his decision to stay behind.
