Mob Nanoni Vampire-tachi ni Kyuuketsu Saremakuttemasu

The main character, Sophia, has been reincarnated as a mob character in the popular vampire otome game "Vampire Academy: Sweet ∞ Blood". In her previous life, she was cheated and betrayed by her boyfriend, and so after being reincarnated, she thought she could live a peaceful life as a mob character, but she ends up being targeted for bullying by Emilia, a bad-tempered orthodox heroine. However, it is discovered that Sophia's blood has the power to make the four strongest vampires, who rule over the vampire race, fall head over heels for her, and this results in a complete reversal of her status with the heroine Emilia! She goes from being a nobody to being treated like a princess, and she ends up being enrolled in a school for vampire nobles where she is doted on by good-looking vampires...! (Source: Manga Mirai)