Boku no Noroi no Kyuuketsuki
In a world where vampire attacks are a serious problem, Isuzu Osaka works to hunt them down, and he decides to enlist the help of the vampire Baroque, a known vampire killer, to hunt the latest criminal, even if that means breaking Baroque out of jail, himself. Though it causes a lot of trouble, the two are eventually allowed to work as a team, exterminating vampires together. I think they're both interesting characters, though Baroque is drawn quite young, so maybe avoid if you're sensitive to "lolicon" type settings.
Moudoku Sugar Syrup
Mizuki is a modern-day vampire who eats semen to survive, even though it tastes pretty bad, until one night poor planning leads to him jumping his classmate Sakura who he finds out has the most delicious semen of all. After that, Mizuki is determined not to lose hold of this great meal, and while he gets Sakura on board, Sakura wants more out of their relationship. I honestly think Sakura is really unfair to Mizuki, especially considering Mizuki is literally starving himself for him. Anyway, I like them as a couple overall. Trigger warnings: noncon, attempted cheating, drunk sex equivalent.
Kyuuketsuki ha shinzo no yume wo miru