Vampire Knight, Hana to Akuma Recommendations
Very beautiful lethal beings, cold to everyone but one special human girl, romance and some humor
Not sure, but this manga reminds me of Vampire Knight, but Vampire Knight seems to be a much darker story.
Found as children, in love with a 'monster' (well, either a demon or vampire), demons drink blood, vampires do too?
Good demons, and bad demons, and good vampires, and bad vampires.