A mysterious high-school girl, named Ayaka, harbors a dark secret. She is a martial arts master and killing machine who must keep her family's martial arts legacy a secret to protect her family's treasure, the Black Belt a 200 year-old family heirloom. This karate Black Belt symbolizes the Kurenai family's continual triumph as the most superior karate family in the world. When the Black Belt is stolen and Ayaka's family killed or abducted, it signifies to the rest of the martial arts world that the Kurenai legacy is no more. As Ayaka accidently reveals her awesome fighting skills in public, the ruthless karate gang that murdered her family and kidnapped her sister discovers her lethal secret. A fateful battle is inevitable as the gang and her now-estranged sister prepare to fight the avenging Ayaka for possession of the highly coveted Black Belt.