Western Seoul train station, 1996. A baby is thrown into a coin locker. She is picked up by a beggar, who names her Il Yeong. When she turns 10, she is sold off to a woman referred to simply as Mother. She is raised by remorseless loan sharks until she is 18 years old, by which time she has become Mother's trusted right hand. One day, Il Yeong is given a task: to stay close to Suk Hyun, the son of a debtor. Over the course of a few days, she becomes friends with the boy and is exposed to a world she never knew existed. She envies the normalcy that other teenage girls enjoy and opens her heart to Suk Hyun. But when his father flees, Mother orders her to kill Suk Hyun. Il Yeong cannot go through with it and by making that single choice, she must now flee from the only family she has ever known.