In the perpetually dark underground city of Lux, its inhabitants live under constant fear, dominated by the oppressive rule of rival criminal factions. Cut off from the world above, these groups only interact through the extraction of "raffia," the mineral that sustains Lux's existence.
This unique substance, found only in Lux, is crucial for "texhnolyze" operations, which allow people to replace their body parts with cybernetic limbs that do not trigger immune rejection. The mysterious "Class" organization researches these transplants and controls raffia production, granting executive power to Organo, a group led by Keigo Oonishi, who has texhnolyzed legs and is said to hear the "voice of the city."
Lux's fragile balance of power shatters when an enigmatic stranger, Kazuho Yoshii, instigates a series of crimes that spark conflicts among the gangs. In the resulting turmoil, new figures emerge: Ichise, a former boxer who was crippled by Organo and recently fitted with texhnolyzed limbs by Eriko "Doc" Kamata; and Ran, a young florist who possesses the ability of foresight. As Lux descends into chaos, both Ichise and Ran find themselves at the center of the city's most severe crisis yet.