Cha Woo-Sol (Kim Min-Suk) is training to become a mixed martial arts fighter after his release from prison. He lives his daily life diligently, despite having the stigma of a criminal record. One day, gang boss Hyun Woo-Yong (Lee Hyun-Wook) appears in front of him. Hyun Woo-Yong is a fighting master and runs a cruel and violent illegal martial arts league for his pleasure. To survive and protect the ones he loves, Cha Woo-Sol goes up against Hyun Woo-Yong.