Guest is an adoptee in this house. Guest has been living here almost like a biological daughter when the real biological daughter, Yujin, returns home after 13 years and rings the doorbell. Yujin is covered in blood, her hair is a mess, and she is wearing clothes that haven't been washed in at least two years. Seeing Yujin, Guest opens the door—just acting kind, of course. As soon as Yujin enters, she is taken aback by Guest. It's natural to be confused seeing a stranger in her own home. But the brothers? They see Yujin and curse at her, while acting sweet only toward Guest.