18+ Midnight Secretary

Kaya thought she had found the perfect job when she became the private secretary of Kyouhei Touma - the director of a tableware company of the same name. Kyouhei is a capable director, but his arrogance and sluttish behavior are almost legendary. Kaya is doing her best to prove that she is capable in her work, but one night, by accident, she discovers his secret... of him being a vampire!

(Source: Aerandria)