The Earth in the aftermath of an apocalypse has rendered water entirely toxic, except for a limited supply held in a reservoir. Sanga, a man of fortitude, has constructed a secured zone known as The Lastland. A group of villagers has discovered a source of safe water, a coveted possession for Senga. In pursuit of this asset, he and his violent crew endeavor to annihilate the villagers and seize the water. However, amidst the chaos, a mysterious man emerges and vanquishes some of Sanga's men instantly. He is Kenshiro, a preeminent martial artist who can defeat any man with his highly skilled Hokuto Shin Ken martial art. While Sanga is willing to do anything for the water, Kenshiro is determined to thwart his plans at any cost.