Twin sisters Anya and Nadya Vdovin grew up in an orphanage, and determined Anya was used to always protecting her sister from any dangers.  However, the girls' paths diverged: Anna became a professional MMA fighter, and Nadya, tired of her sister's tutelage, fled to Japan in search of her own path and freedom.  After years of separation, Anya receives an alarming message from her sister, in which she asks for help.  The girl tries to get at least some information, but all efforts are in vain.  Then Anna decides to go to Japan, where she will have to enter into an unequal duel with the Yakuza, who sold her sister into sexual slavery.