Princess Nightmare

Little is a vampire girl, not blood-related to the two who look after her: Radou, who treats her like a younger sister, and Vlad Dracula, who serves as a father figure. When their hiding place is discovered by vampire hunters, the three flee to Japan, where they spend their days asleep and their nights as themselves. Little meets a human boy and finds herself drawn to ordinary life. Radou is firmly against it. Dracula permits her to enroll in school, and she makes friends and genuinely enjoys it. Then a messenger arrives with instructions to return to the devil world.