In the wake of World War III, the world has fallen into anarchy and water is endlessly scarce, forcing the last of humanity to fight for survival. Two rival martial arts orders, the North Star and the Southern Cross, once stood for order, but a brutal betrayal shattered both sides. Shin, a Southern Cross adept, turned on his masters and killed Ryuken, the North Star master, leaving Kenshiro as the sole heir. Shin then abducted Kenshiro's fiancée, Julia, and holds her captive in a towering fortress, ruling the land with a merciless militia known as the Crossmen, led by the ruthless enforcer Jackal, whose head is bound in leather bands after Kenshiro left him scarred in an earlier fight.
Years pass, and Kenshiro roams the wasteland with a quiet, unyielding resolve. He fends off a gang led by the bandit Zeed who attacks the shelter that sheltered him, then heads toward Paradise Valley, one of the few remaining wells of pure water. There, he encounters the orphaned siblings Bat and Lynn. A swift demonstration of his pressure-point technique restores Lynn’s sight—the sight of a girl who watched her parents murdered by the Crossmen—and though Lynn pleads with him to stay and protect them, Kenshiro presses on, haunted by the weight of the world he can’t fully save. Bat follows, hoping to coax him into joining a burgeoning resistance, but Kenshiro remains wary and distant.
The Crossmen descend on Paradise Valley, seize the well, and Jackal orders Lynn’s execution for sedition. She escapes that grim fate by threatening to reveal Kenshiro’s whereabouts, yet she’s captured and taken prisoner to be used as leverage. When Lynn’s screams echo in Kenshiro’s head, he turns back, and he and Bat infiltrate the city to free her. The rescue is costly: Bat is mortally wounded in his clash with Jackal, and Kenshiro, choosing mercy, spares Jackal and sends him back to Shin to announce Kenshiro’s arrival.
On Shin’s orders, Jackal escorts Julia to the tower’s basement to keep her out of Kenshiro’s reach. The cat-and-mouse game intensifies as Jackal attempts to abuse and kill Julia, while Kenshiro breaches Shin’s tower and confronts him in the throne room. Shin leverages Kenshiro’s shock with false reports about Julia’s fate, momentarily sapping Kenshiro’s resolve, but a sprouting bud—the emblem of a seed Kenshiro had given Julia long ago—reignites his hope. With renewed determination, Kenshiro defeats Shin and ends his rule. In a brutal turn of fate, Julia finally frees herself from Jackal by tearing away his bandages, causing his head to swell and explode. The story closes with Julia reuniting with Kenshiro as the remaining Crossmen bow in deference, acknowledging the dawn of a fragile new order led by Kenshiro and Julia.
