Yang Jisu is a top student at her high school with dreams of becoming a novelist. Her life sails along with her gorgeous boyfriend Dohyeok and trusty gal pal Juyeong. All is well until the notorious hunk Hyeseong swoops into the picture. He is the so-called “Jisu killer” who has dated four other girls named Jisu at school. The serial boyfriend approaches Yang Jisu as his fifth and final target. She does her best to fend him off, but she can’t help noticing something uncanny about him. He knows too much about her, especially when it comes to her dates with Dohyeok. Will she get to the bottom of this mystery and avoid what seems like a fated end?