This series is about a 19-year-old girl, Yoo Min, who was being abandoned after the death of her mother. She lives alone with her adopted brother, Kang Pyo. She accidentally meets Seung Jae, the younger brother of Min Jae. By chance, Yoo Min actually had a crush with Min Jae, a doctor who treats her brother illness for a long time. To fight off his mother demand, Min Jae gets in an engagement contract with Yoo Min and they all end up living at Min Jae's house. Unexpectedly, Yoo Min and Seung Jae are going to the same high school. From there, Seung Jae secretly loves Yoo Min. On the other hand, Yoo Min's father who got amnesia from a car accident is looking for her again when 15 years ago, she had been abandoned by two women who worked at the restaurant. The conflict comes when the people who are living in Min Jae's house are actually related to Yoo Min's abandonment. They are the ones who stole the inheritance and abandoned her when she was four year old.

该剧讲述了金女士强迫民在订婚，而民在却在等待已失去音信的恋人。被母亲逼得没有办法的民在只好求助惠英，假装订婚以敷衍母亲，两人订下契约婚姻。这样一来，十九岁的惠英成了承在未来的嫂嫂，令爱慕惠英的承在心情矛盾。

대학을 졸업하고 사회의 구성원이 되려고 몸부림치는 젊은이들의 고군분투기로, 돈 안 되고 때깔도 안 나는 ‘배고픈 수학자’가 되기 위해 도전하고, 마침내 성공하여 집안의 우환덩어리에서 능력 있는 젊은 청년으로 거듭나기까지의 성공기를 통해 이 땅 40만 젊은 백수들에게 짜릿한 희망을 선물하고자 한다.