Ravage Me, Master

No thanks to the debt her father saddled her with, Iroha goes to work for Rentaro Komatsuno, a moneylender. A rumor surrounds Rentaro... He'll lend any amount of money, so long as it's for a woman. But, in reality, Iroha learns the unspoken catch. Rentaro is a vampire who sucks women's blood in exchange for a loan. The moment he sucks their blood, intense pleasure strikes, and all the female customers become enraptured by him. Iroha wants to run from him, but things change when Rentaro begins to seek blood from her, as if there's something special...

(Source: MangaPlaza)