To settle a debt incurred from a childhood incident, Taeeun's father provides Sooyoung's family with one million won each month. Now adults, their paths cross again at the office, where he is the new team head and she is the most junior member. Thus begins their tense and complicated workplace dynamic. "Team Leader, why are you so kind to me?" "Because I am indebted to you." "Then why do you treat me so coldly?" "Because I don't know if that is a debt I'm meant to bear."