2057, Hemisphere, a man-made city in Tokyo Bay, has wiped out virtually all crime by introducing the quantum AI system "XEVEC", through which the "law" acts as a physical force to protect all citizens. Hemisphere is a "utopia", an ultra-nomocratic society in which the righteous are rewarded and permanent peace is guaranteed. Or so I thought. Until that incident...

(Source: Kodansha, translated)