Five years ago, Han Yeol Moo jumped in the car of Prosecutor Gu Dong Chi. Gu Dong Chi fell in love with her at first sight. He asked her to meet him 10 times and then decide if she wants to continue their relationship. At the 10th meeting, Han Yeol Moo found some crumpled up paper in his backpack and left without saying anything to Gu Dong Chi.
Now, Han Yeol Moo begins work as a trainee prosecutor and meets Gu Dong Chi in front of his office. She is assigned to the team where Prosecutor Gu Dong Chi works. Gu Dong Chi, still holding feelings for her, tries to help her become the best prosecutor, but Han Yeol Moo holds a secret.