Six months ago, a massive earthquake sunk a massive Japanese city into the ground, burying it from the outside world. The survivors split themselves into three groups: A, with normal salarymen; B, with criminals and lunatics led by the towering Mad Saurus; and C, an all-female group. However, once food supplies began to dwindle the once-kind men of the A group brutally gang-raped the women of the C group, causing the ladies to seal themselves up deep within the ruins. Now, the A group is working towards digging their way to the surface when they unearth Violence Jack, a massive giant. Though the A group wants Jack to help defend them against the B group, he ultimately chooses to protect the C group against all of the others. A bloody civil war approaches - will anyone escape alive?