Jin-A is hurried by her parents to get married and she's busy with her job. One day, she says goodbye to her delusional lover, Gyu-Min. In addition, she finds out from her best friend Kyung-Sun that Gyu-Min cheated on her. Meanwhile, Kyung-Sun's younger brother, Joon-Hee, returns from the United States and appears in front of Jin-A.

Gyu-Min pushes to get back with Jin-A. Joon-Hee is there and says that he's Jin-A's boyfriend, driving Gyu-Min away. Meanwhile at the company drinking party, Jin-A is caught between her bosses. She responds at the sexual harassment with a smile. Her colleagues tell their juniors not to imitate that behavior, even if they long for her.

Jin-A pushes back Gyu-Min, who wants to get back together. He misunderstands that Jin-A has an affair with Joon-Hee. Still, Gyu-Min doesn't back off. Meanwhile, Jin-A's mother, Mi-Yeon, gets mad at the wedding invitations that arrive one after another, and calls Gyu-Min home. Jin-A gets angry at her mother's selfish behavior...

While having dinner, Jin-A's father, Sang-Ki, finds out that Gyu-Min has an affair. They end up quarrelling. Gyu-Min complains that not only himself but also Jin-A has an affair. In such a turmoil, Joon-Hee is taken by Jin-A's younger brother Seung-Ho to visit their house. Then, Gyu-Min says that Jin-A's partner is Joon-Hee...

Jin-A, who's haunted by Gyu-Min, decides to erase the past and tries to dispose of her memories. Meanwhile, Joon-Hee finds out that Jin-A has come to see him. They're getting closer, but for some reason the timing isn't right. Finally, the decisive moment will arrive.

After getting to know each other's feelings, Jin-A and Joon-Hee start their secret relationship. On the other hand, Gyu-Min becomes more obsessed with Jin-A and pushes her into a store. Jin-A desperately resists over Gyu-Min who's trying to kiss her. One day, Joon-Hee follows Jin-A to her business trip and spends a sweet time with her.