Douka, Chi wo suutte kudasai~ Tensei shitara Kyuuketsuki Hunter no Akuyaku reijou deshita

I can't kill my favorite vampires! I've accidentally been reincarnated into the world of "Red Nosferatu," a romance otome game in which you fall in love with handsome vampires. And, of all people, it turns out to be Diana, the villainess "vampire hunter" who kills all the girls she likes! I'm going to die whether I kill the vampires or not! She must somehow avoid this death flag...!