Oh Yeon Doo is an optimistic online lecturer who teaches the Korean language. After going through many hardships, she finally gets a stable home and career which allow her to prepare for marriage. However, a new dilemma of becoming a single mother occurs. That is when she meets her doctor, Gong Tae Kyung. Although he chose to be a misogamist, a man who wishes to avoid marriage and a woman who is willing to birth a baby without a father starts a relationship. Hence, the contract romance begins with the baby as collateral. Would their impudent lie be able to fool their families to the end?