Sion, a police captain, took charge of the mission to infiltrate a criminal organization after her younger sister was abducted by unknown criminals. Driven by the urgency to rescue her sister, she risks falling into a trap and being exposed. In order to gain freedom for herself and her sister, Sion is forced to participate in illegal fights and is given tough conditions to win. Her determination are put to the test as she fights to overcome the challenges and emerge victorious. Sion won’t give up and ready to do everything to save her sister, but as the sisters continued to participate in more matches, it became apparent that the sisters had discovered a new passion, deviating from their original goal.