Five years ago, Yeol-Moo (Baek Jin-Hee) jumped in the car of Prosecutor Dong-Chi (Choi Jin-Hyuk). 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, Yeol-Moo found some crumpled up paper in his backpack and left without saying anything to Dong-Chi.
Now, Yeol-Moo begins work as a trainee prosecutor and meets Dong-Chi in front of his office. She is assigned to the team where Prosecutor Dong-Chi works. Yeol-Moo is very enthusiastic about her work. Dong-Chi, still holding feelings for her, tries to help her become the best prosecutor, but Yeol-Moo holds a secret.