After nuclear devastation transforms the world into a lawless wasteland in 199X, Kenshiro embarks on a perilous journey to confront Raoh, the tyrannical Ken-oh who rules over the fractured remnants of civilization. Along the way, he must overcome a gauntlet of formidable adversaries—including the deranged killer Heart, the skilled Nanto Sei Ken practitioner Shin, his own treacherous stepbrother Jagi, and Souther, the mightiest warrior of the Nanto Sei Ken school. To overcome these obstacles and ultimately challenge Raoh's dominion, Kenshiro delves deeper into mastering the legendary martial arts techniques of Hokuto Shin Ken, an ancient discipline capable of reshaping his destiny and that of the wasteland itself.