The Maid is a VampireMaid-san wa Kyuuketsuki; メイドさんは吸血鬼; The Maid is a Vampire

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.