About the title
Young architect Seo-jin has been unable to recover from his wife's death for six months. He lives in his parents' large house, suffers from post-traumatic stress, and struggles to connect with his young daughter. Suddenly, Seo-jin gets a call from an orphanage informing him that his younger sister Yu-jin, whom he lost in an amusement park more than 20 years ago, has been found. The parents happily welcome their newly found daughter, who showers them with care, but Seo-jin finds his sister deeply suspicious.