Texhnolyze takes place in the city of Lux, a man-made underground city that has crumbled after years of neglect and lack of repairs. Citizens of Lux have come to refer to their home as simply "The City" and treat it as though it has a mind and will of its own. Three major factions battle to control Lux: Organo, a group of "professionals" who collaborate with the criminal underworld that controls Texhnolyze (prosthetics), the Salvation Union, a populist group that seeks to disrupt Organo's business, and Racan, a collection of young individuals with Texhnolyzes that use their abilities for personal gain. Ichise was once an orphan who has made a place for himself in Lux as a prize fighter. One day, a fight promoter grows angry with him and the altercation that follows results in Ichise losing an arm and a leg. Before death can take him, Ichise is found by the scientist Eriko Kamata, who uses him as a test subject for her newly designed Texhnolyze. With these powerful new limbs at his disposal, Ichise begins to work for Oonishi, the leader of Organo. He soon meets a mysterious young girl, Ran, who has the power to see possible futures. Together, they soon realize that Lux is on the brink of war and collapse, and that they may be the only ones who can save The City.

Vash the Stampede is the man with a $$60,000,000,000 bounty on his head. The reason: he's a merciless villain who lays waste to all those that oppose him and flattens entire cities for fun, garnering him the title "The Humanoid Typhoon." He leaves a trail of death and destruction wherever he goes, and anyone can count themselves dead if they so much as make eye contact—or so the rumors say. In actuality, Vash is a huge softie who claims to have never taken a life and avoids violence at all costs. With his crazy doughnut obsession and buffoonish attitude in tow, Vash traverses the wasteland of the planet Gunsmoke, all the while followed by two insurance agents, Meryl Stryfe and Milly Thompson, who attempt to minimize his impact on the public. But soon, their misadventures evolve into life-or-death situations as a group of legendary assassins are summoned to bring about suffering to the trio. Vash's agonizing past will be unraveled and his morality and principles pushed to the breaking point. [Written by MAL Rewrite]

This is the other side of Tokyo, a Tokyo of a different color. There, various tribes are living. The SARU from Japan's Musashino, WU-RONZE of Bukuro, and HANDS of Shindyuku... Young men living in the city...the public of modern times builds a home out of corruption, these young men of the sordid side of life, a side called "reality," are depicted here! (Source: AnimeNfo)

Creatures known as Shokujinki have been secretly living alongside humans for hundreds of years. Though they may look like humans, Shokujinki are able to transform into uncontrollable beasts with gigantic claws and consume humans to survive. The equally secretive Kifuuken dojo specializes in killing Shokujinki by cutting off their arms, and is the only force preventing unchecked Shokujinki domination. Toshihiko Momota, the son of the leader of the Kifuuken, is instantly charmed by a mysterious woman named Yuka Kamitsuki. Their relationship is complicated, however, because unbeknownst to them both, Yuka is a Shokujinki and Toshihiko is sworn to kill her. Meanwhile, the Kifuuken is having a crisis of confidence as Toshihiko's brother Kazuma pushes against tradition and tries to modernize the Kifuuken. As emotions are strained and the secrets of both the past and present are revealed, who will live, and who will be eaten? [Written by MAL Rewrite]