A mysterious high-school girl, Ayaka, 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. After the Black Belt is stolen and Ayaka’s family is killed or abducted, 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.