Ji-o's luck runs out when she gets injured before the tryouts for the national taekwondo team. In the middle of facing what seems to be the biggest crisis of her life, she meets Gyeol, a mysterious boy who changes her life forever. He's the definition of a bad boy with a good heart, and she finds herself unable to resist his charms. However, she might be playing with fire as he's someone who's involved with the wrong crowd. Is falling for Gyeol worth the risk?