The Maid Is A Vampire summary:

15-year-old Alfred Saionji, heir to the venerable Saionji family, spends his days striving to become a first-class gentleman while enduring strict family rules.His solace comes from his maid, Magly.Thanks to her, a cool and beautiful maid, Alfred's life has become colorful, but...In fact, her true identity is a vampire. Once she sees or sucks blood, her very naughty nature comes out, and Alfred immediately has his blood sucked at her command...This is a love story between a boy who seeks the strength to protect a girl and a clumsy, naughty vampire maid who is in love with him.+