But normally, they're soulless animated corpses. They have bad breath and they drink blood to stay alive. What's sexy about that? :)
There are many different kinds of vampires in folklore. From rotting corpses that drink blood in a very messy way alays killing it's prey, to those alive enough to leave half-breed children (as in they are more a race of magicals than undead).
Most current representations of vampires come from Dracula or Carmilla. They represent a godless existence, which by it's nature is repulsive but also devilishly seductive. Later the religious undertones were removed and we got to, say, Twilight, where mormon christian heroine sees nothing wrong in being turned into a vampire to preserve her love forever and vampires can enter the sanctity of marriage.
Of course, japanese literary tradition is even less influenced by christianity (or monotheism in general), so gothic vampires lost their unholy and disgusting characteristics even faster.