Jung Nicole, the heiress to the Jung’s Enterprise. Since birth, Nicole was showered with massive of love especially since she is the only child in the family. Her life was thought to be perfect, until she lost her parents at the age of 8, when they tried to rescue her from being captured away by the kidnappers. Nicole developed an unreasonable and proud personality since there was no one to guide her in life. The only person she trusted with her life is her childhood friend, Son Dongwoon, who betrayed her in the end. Now to prevent herself from losing everything, Nicole has only one choice, and this could work out only when her arch enemy is in this with her.

Kim Kibum, Key, comes from an average family. He was abandoned by his parents on the streets and was picked up by Kim Soogeun, who treated Key like his own grandson. Even though there are only two of them in the family, Key never felt lonely in his life. All he wanted to do is to earn lots of money so that his Grandfather can retire instead of having to continue working to earn his school fees, this is also the reason why Key was often absent from school and was labeled as a problematic kid by the teachers. Key hated Nicole even though they have never interacted before; he hated the way she behaves as if she owns the world. And never have he thought before that, he’s going to be the most important weapon for her plan.

Goo Hara, one of the most well-liked student in the campus. Despite her good looks and results, Hara was always kind and humble; however she had one secret that no one else knew, until Nicole found out unintentionally.  After Nicole promises to keep it a secret for her, the two of them gets to know each other better, and Hara then understood that Nicole is not what she portrayed herself as. Hara was the one who thought of the plan to help Nicole when she was on the brink of having everything taken away. Hara was in love with the captain of the basketball team, Choi Minho, who has his eyes only for his step sister.

Choi Minho, a popular figure in the campus. He always seems cool and unapproachable because he barely smiles. Though he doesn’t show it out, but Minho is actually a fragile person who could breaks easily.  He is also one of the person who found out about Goo Hara’s secret, but he have never mentioned it to anyone else including herself, which is why Hara have no idea that aside from Nicole, there was someone else who knew about it. Out of sympathy, he helps Hara out a lot which led her to misunderstand that he did it out of love, when the fact is Minho’s heart was already captured by his step sister.

Son Dongwoon, Nicole’s childhood friend who have always been there for her. He genuinely loves Nicole and has always protected her, despite her throwing temper at him often. Even though he was the one who tricked Nicole into signing the contract, but he have never wanted to destroy her at all. He wished he could tell her the truth, he wish he could tell her how much he loves her not just as a friend. But when Nicole started her plan, he knew he had to stand against her despite wanting so much to be by her side again. Dongwoon have never realized that what he did was about to take Nicole away from his life, forever.