From Digital Manga Publishing:
The time is the first decade of the twenty-first century. The place is Tokyo, Japan. Specifically, the ward known as Shinjuku. An 8.5 earthquake shatters Shinjuku, destroying buildings and streets and turning the bustling ward into a haunted ghost town plagued by the paranormal and the bizarre. Scientists and ESP investigators along with criminals, enterprising yakuza gangs and mutant cyborgs come to “Demon City”; some to study the effects of the Devil Quake, others to commit heinous acts of savage violence, and still others to live freely in this lawless town on the edge of the abyss. This is the world of Demon City Shinjuku and how it all began. It is now 2030 and President Kozumi Rama of the World Federation is attacked by an otherworldly demon Reba Ra, an evil sorcerer of immense power. The only person who can stop Ra is yogi Master Agni Rai’s former apprentice, Genichiro Izayoi but Genichiro is dead.
His son, Kyoya Izayoi, a high school student and the inheritor of Izayoi’s killer nenpo martial arts technique, now enters Shinjuku to try to stop Sorcerer Ra from unleashing the ultimate horror in Demon City. The fate of Shinjuku and the rest of the world hangs in the balance.