The I.O.U. is a company who works secretly, providing justice using methods which may or may not break the legal laws. 25 years after it was founded, The I.O.U. recruits eight different girls, insisting that they owe the company and to pay for their debts they must become the latest unit named: Oh My Girl. Hyojung is an innocent girl who has led most of her life digging up ginseng or something and becomes the leader of the group. JinE is a girl with a mo