Oh Woori (Im Soo Hyang) has vowed to remain a virgin until she marries her boyfriend, devoted police officer Lee Kang Jae (Shin Dong Wook). But disaster strikes when a terrible mix-up turns her routine medical exam into an artificial insemination procedure! She later discovers that her baby’s biological father is Raphael (Sung Hoon), the CEO of a cosmetics firm, who's going through an acrimonious divorce with his wife. When Raphael learns he is to be a father, things get very complicated – particularly when he realizes he and Woori have a past connection! Is there any way out of this mess?