[6][7] A baby is found abandoned inside a coin locker at Western Seoul train station in 1996.

Mother is the boss of a loan shark and organ trafficking crime ring in Chinatown, Incheon; she has held on to her position of power by being dispassionate and calculating, and by keeping by her side only those of use to her.

Mother decides to raise the young child after she shows toughness and smarts, eventually grooming her for a position in her organization as her personal debt collector.

One day, Il-young is given a task to collect debt from Suk-hyun (Park Bo-gum), the son of a debtor.

Over the course of a few days, she is initially taken aback by the guy, who doesn't seem afraid of her and even shows her kindness and openness when talking about his own struggles, before starting to develop feelings for him.