I Won't Let Mistress Suck My Bloodご主人様には吸わせません！; Goshujin-Sama Niwa Suwasemasen!

Matilda is looking for a job and a place to stay, and ends up in a large mansion known as the "Haunted House." The owner of the house, August, is a beautiful, soft-spoken woman, and Matilda is attracted to her and decides to work for her as a maid. However, that night, Matilda finds that her master has transformed.