Because of an incident in their childhood, Tae-eun’s father incurred a debt to Suyoung’s family and has been sending them 1 million won every month.
Years later, the two meet again as adults—he as the newly appointed team leader and she as the youngest member of the team—beginning a tense and delicate office life together.

“Team leader, why are you so kind to me?”
“Because I owe you a debt.”
“Then why do you seem to dislike me?”
“Because I’m not sure that debt is really mine.”
“Because I’m not sure that debt is really mine.”