Vampire Hunter D Vol. 4 (Seinen Manga)

The City, a tiny metropolis of a few hundred sheltered citizens floating serenely on a seemingly random course a few feet above the ground, has long been thought safe from the predation of marauding monsters. It seems like a paradise.  A paradise shattered when an invasion of apparent vampire threatens the small haven. While the Vampire Hunter known only as "D" struggles to exterminate the scourge, a former denizen of the city, the attractive Lori Knight, and the brash John M. Brasselli Pluto VIII seize control of the city, lurching it onto a new and deadly course.  D's travails are just the beginning.