Slumking

The Kanto Hell Earthquake has demolished the metropolis completely. After the earthquake, the Slum King kidnaps girls to sell them off as sex slaves. Mari is wandering on a devastated field looking for her lover Ken. But she is also kidnapped by them. While she is tortured and trained as a sex slave, Ken saves her. Ken has to become a member of Slum King's gang, but the king sets one condition; in return for releasing Mari, Ken has to kill Violence Jack.