A naive stalker girl. The strongest man in Ikebukuro. A shut-in doctor with questionable credentials. A hedonistic informant...and the "headless rider" astride a pitch-black motorcycle!? As their paths cross, this eccentric cast weaves a twisted, cracked love story...

    Yuichiro escapes from captivity and joins the Japanese Imperial Demon Army. But before he's allowed to fight vampires, he has to complete his first, terrifying mission-- make new friends with his fellow aspiring monster slayers!Yuichiro and his friends are kept as vampire fodder in a creepy institution masquerading as an orphanage. One day, Yuichiro's dreams of fighting back are realized when the orphans stage a daring escape. But things go horribly wrong, and his dream is kept alive at a cruel price.

    They descend from the skies. They have a hunger for human flesh. They are everywhere. They are parasites, alien creatures who must invade - and take control of - a human host to survive. And once they have infected their victims, they can assume any deadly form they choose: monsters with giant teeth, winged demons, creatures with blades for hands. But most have chosen to conceal their lethal purpose behind ordinary human faces. So no one knows their secret - except an ordinary high school student. Shin is battling for control of his own body against an alien parasite, but can he find a way to warn humanity of the horrors to come?

    Transported back to Japan's feudal era, high school student Kagome accidentally releases the feral half-demon dog boy Inu-Yasha from his imprisonment for stealing the Jewel of Four Souls.