Season 1

Lee So Hyun, a high school dropout and a runaway girl, always thought that her dad has passed away. However, it turns out that he just abandoned her. Enough is enough. Having nothing more to lose from her already miserable whole 19 years of life, she decides to hear her dad's side of the story. Knowing that her dad doesn't even realize her face, she rents a house near her dad's and slowly steps into his life.

So Hyun plans out how to ruin Jae Young's happiness, and decides to get rid of his loved ones out of his life. So Hyun starts to hang out with Yoon Ho more often so she can naturally bump into Bok Hee, her dad's girlfriend. So Hyun thinks that Bok Hee will be disappointed to find out that she is actually Jae Young's daughter and will break up with him in the end. Meanwhile, So Hyun takes revenge on Jun Sik first.

So Hyun tells Bok Hee the truth and apologizes for lying to everyone. Even though Bok Hee promised not to tell Jae Young about it, So Hyun changes her plan and wants to get rid of Bok Hee as soon as possible. Meanwhile, Jae Young suggests going on a trip together, and So Hyun decides to carry out her new plan during the trip.

After So Hyun finds out the truth about Jae Young, she regrets what she has done to everyone, but it was too late to take it back. She goes back to Yu Mi to spit her anger out at her. However, she starts to think that she was the only problem, not the people around her. Therefore, she decides to disappear and leave them alone.