Hi there, this time I post in the correct forum (I think) :-)
I saw that j-novel acquired this novel. Full title is " Seriously Seeking Sister! Ultimate Vampire Princess Just Wants Little Sister – Plenty of Service Will Be Provided " (damn long !) or Tonikaku imōto ga hoshii saikyō no kyūketsuki wa mujikaku gohōshichū / とにかく妹が欲しい最強の吸血姬は無自覚ご奉仕中! in japanese.
Does anyone know it ? As for me, the cover and the title ("plenty of service" :D ) make me think it will be a yuri com ;) What do you think ?
(https://cdn.animenewsnetwork.com/thumbnails/max450x450/cms/news.2/145967/sister.jpg)