MegaTokyo 2027: Relentless technological development has resulted in the creation of Boomers.

These are artificially intelligent androids with the potential to free mankind from physical labor; but anything that can be used can also be misused.

After disasters have all but destroyed the Earth, leaving entire cities buried, one man named Violence Jack tries to avert a civil war brewing among the wretched inhabitants of a subterranean metropolis called Evil Town. The known world is now a nightmare after a series of natural disasters. Survivors struggle to survive the harsh conditions. Evil Town is divided into three warring factions each fighting for supremacy.