After the death of Leon Soo-Yun's father, her mother Leon Min-Soo couldn't handle the Leon Cooperation Alone. She wanted her daughter to join the company as a CEO, but Soo-Yun never agreed with her. 
She always missed her father. Soo-Yun believes that her father's death wasn't a normal death it's was murder. She wants to find the real reason behind her father's murder. Of course, she was a lawyer so this is an opportunity for her. 
After that her mother decided to hand over the company to a very responsible person, she talked to her best friend Mrs. Jang who was also the mother of a very famous CEO at young age Jang Jun-Sang. 
They decided to arrange the marriage of their beloved children Jun-Sang and Soo-Yun. Soo-Yun and Jun-Sang agreed to the marriage but there was an issue, Jang Jun-Sang was in love with someone else, and Soo-Yun was aware of it, but she didn't expect that she was going to pay for it. Jun-Sang will make her regret marrying him.

Nightmare