Ji-oh, a senior in high school who was injured ahead of the National Taekwondo Competition, while handling the biggest crisis of her life meets Cha-gyeol, a handsome and mysterious young man, he's the definition of a bad boy with a good heart. However, the people Gyeol is surrounded by seem to be dangerous. She knows she should stop her interest in him. Would that be alright if she'll be able to... Love him?