Dokgo Ma-te (Jang Keun-suk) is a pretty boy. His mother dies without giving him the password to meet his father, whom he never knew. Ma-te's mother gives it instead to Hong Yoo-ra (Han Chae-young), an ex-heiress who was once the daughter-in-law of a wealthy family. A family that she thinks Ma-te's father is the chairman of. Yoo-ra promises to give him the password if he conquers several women and learns valuable lessons from each of them so as to conquer Na Hong-ran, Yoo-ra's ex mother-in-law and the Chairman Park Ki-suk's wife, who is evil and ruthless. But then Kim Bo-tong (IU), an ordinary girl from a poor background decides to aid Ma-te in pursuing his father's heels. She has had a huge crush on him since high school and is willing to do anything to help him succeed. Despite himself, Ma-te falls for Bo-tong.
But Choi David (Lee Jang-woo), who is also the Chairman's secret son and is like the male Bo-tong, falls for her too, leading into a conflict of romance and deception.
A boy who discovered as early as kindergarten that he was prettier than most and could get special treatment because of it. During his school years he never once had to bring lunch to school, and now only has to glance at designer stuff in stores for rich women to purchase them for him. He discovers he has a wealthy father who he doesn't remember. His role within the drama is to learn different things from dating/seducing ten wealthy ladies, so that he can eventually undertake the role of meeting with his father.
An average girl from Ma-te's neighborhood who's had an unrequited crush on him since junior high. She is innocent and free hearted who is head over heels in love with Ma-te and helps him through his journey of overcoming troubles to meet his father. Her name, Bo-tong means 'average' in Hangul.
A friendly, free-spirited marketing director who falls for Bo-tong and helps her out. He has a strange past too, however also changes the story with his funny and warm personality. He meets Bo-tong when she starts to sell her belongings to earn money and immediately gets attracted to her innocent charm.
The glamorous, successful woman Ma-te wants but can't get. She makes a game of "training" him and tells Ma-te to seduce ten of the most eligible bachelorettes in the city first. She has had a difficult life filled with torture as she can not see her own child nor talk to her husband from the harsh rule of the wife of the chairman.
