An honest cop has to compromise with his principles when he is told to find a scapegoat for a high-profile serial killer case in exchange for a big promotion.

Lee Ha-yeon is the wife of the heir to Ilsin Group and even so one of the richest women in South Korea. She is respected and enjoys the luxury of her penthouse. But one day she is found dead in a hotel room. The police thinks she had been poisoned and is investigating the case very secretly to avoid a scandal. But they have no clue what happened to Lee Ha-yeon. They are no signs of a forced entry and there are no fingerprints at all. The police are even wondering what Ha-yeon did in this hotel room. But the police is joined by Ha-yeon's estranged sister Ha-jong who received a camera from her sister just shortly before her death. The camera reveals that Ha-yeon had several sex chats and meetings. And they also get to know that Ha-yeon had been blackmailed and finally they witness how she was killed. Ha-jong feels guilty as she couldn't help her sister and she becomes desperate to find the murderer.

Yeon-woo is a 24-year-old youth working at the post office in a small town. She's in the golden age of her days, except she has an innocent and introverted personality, and she's far from the usual storm and gale of life. She's hasn't even tried drinking yet, let alone coffee and those around her consider her still young. However, she's completely different from her family. She has an irresponsible father, an impossible brother, a shameless grandfather and a very young brother. All they ever care about is...women. Her father is already head over heels for a woman from out of town and her brother is also after the girl working at the coffee shop. Her grandfather, who's after a granny at the nursing home and her youngest brother whose heart is out to the teacher, are nothing compared to her father and brother. The only person who deserves to be called the breadwinner of the family is her mother who runs a salon.

Il-young tries to get away from her adoptive mother because she does not want to get involved in her mother's criminal activities.