One of the members of elite special operations team of the government, Super Junior, goes undercover in an attempt to catch the boss of the largest mafia gang in South Korea. In order to catch the boss, he have to get close to his daughter.

Ryeo Seon is the daughter of a rich and notorious mafia boss. She grew up in a pretty much perfect family without knowing of her father's real occupation. She runs a fashion boutique and cafe in one of the high end neighbourhood in Seoul with her own money. One day, a handsome guy entered her life and made her fall hard in love for him.

What will happen when Ryeo Seon finds out the real occupation of her father? And how will she react when she finds out that the man she loves is just using her?