Doo-rim works day and night to save money for her ill grandmother. But things only worsen when her grandmother collapses from shock when her lodge money gets stolen. One day, she saves a man who was about to get hit by a falling brick while working at a construction site. This man turns out to be Yi-hyeon, the eldest son of O-seong Construction Company.

Doo-rim accepts Yi-hyeon’s offer and starts living in his house. She is trained to act perfectly like Yi-gyeong at the arranged meeting of the two families. On the meeting day, Doo-rim sees Bong-sook, the thief of her lodge money and starts chasing her down when she runs into Gang-joo. Gang-joo doesn’t believe in love due to his traumatic first love experience and treats marriage like a business.

Doo-rim and Gang-joo start to get to know each other better. Gang-joo starts falling for Doo-rim when he sees her laugh loudly and take care of her grandmother. Doo-rim is assaulted by a tomato thrown by an employee fired from the department store and wins a cake eating contest with a face full of cream. Gang-joo is dumbfounded by such actions.

Roomi has doubt of Doo-rim's identity. Meanwhile, Yi-gyeong keeps watching the whole situation. The reason Yi-hyeon disappeared, she believes in the curse that Gang-joo’s family is cursed – the bride of the first son always dies. Yi-gyeong didn’t believe in the curse from the beginning.

Doo-rim falls into a trap which has been planned by Roo-mi. Roo-mi forces Doo-rim to call Gang-joo just for fun. Doo-rim reluctantly calls Gang-joo and he appears like a prince. He pays the whole meal and treats Doo-rim like a princess.

One day, a ring goes missing just before the opening of a jewelry exhibition at the department store. Doo-rim finds out it was her friend, Jin-joo who stole it. Doo-rim tries to help Jin-joo by sneaking the ring back in but gets caught by Roo-mi and is falsely accused of being the thief. Gang-joo is disappointed and feels betrayed. But only Yi-hyeon believes in her innocence and cheers her up.