The twin sisters Anya and Nadia Vdovin grew up in an orphanage, and the determined Anya is used to always protecting her sister from any dangers. However, the girls parted ways: Anna became a professional MMA fighter, and Nadia, tired of her sister's care, fled to Japan in search of her own path and freedom. After years of separation, A does not receive an alarming message from her sister, in which she asks for help. The girl is trying to get at least some information, but all efforts are in vain. Then Anna decides to go to Japan, where she will have to engage in an unequal duel with the Yakuza, who sold her sister into sexual slavery.