Denizens of Lux have come to call it "The City" and treat it as a sentient force. Three factions vie for control of the city: the Organo, a strictly professional conglomerate with ties to the criminal underworld in the prosthetics business; the Union, a fanatical populist group interfering with Organo's affairs; and Racan, a marauding group of Texhnolyzed youths.

Rikka is a ninja descendant. Her grandfather Hyoe is the last chief of their ninja clan and her father is a cyborg researcher. Both are killed when a weapons' company raids his lab to use his research. Rikka sets out to avenge their deaths.