Mr. Vampire Wants Me EveryDay

There is a stretch of ground vampires keep closed to humans, and a young woman walks into it without knowing. She is caught and about to be bled dry when the oldest and strongest vampire lord stops it, because her blood is the one matched to him. They spend the night together. In the morning she runs, gets to her office, and finds the man behind the desk she reports to is him. He owns most of the city and has money nobody can count, and he was in her bed hours earlier. He tells her what she is to him now, part bride and part property, and the terms are not open for discussion. She keeps coming to work. He keeps behaving in the office as though nothing happened, then does not, and the arrangement between them starts pulling in directions neither of them planned for.