Yoon Soobyul is a rich and obedient daughter of one of Korea’s richest family. She has a twin sister, Yoon Baeyul, who is a party animal, reckless and always causing trouble. The Yoon siblings are famous for their opposite yet generous personalities.

After being fed up of Baeyul’s character, their parents decide to get her married. But Baeyul has something totally opposite in her mind. She has a lover, Onew. So on the night of her marriage, she elopes with him leaving the whole Yoon family in chaos and on the verge of losing their respect in the society as Baeyul’s to be husband was no other than another rich family’s son, Kim Kibum or for short Key.

To avoid her family from losing their stature in front of so many people, Soobyul jumps into her sister’s shoes and dress and walks down to aisle to marry Key. Key and Soobyul get married without anyone else than the Yoon family knowing.