Kiyo Katsuragi is a young girl still attending school, when she is about to inherit her grandmother's mansion given to her mother. When she enters, she finds out she is also living in the mansion with two vampires, Kuroboshi and his servant Alshu. Things get even crazier when Kuroboshi decides to make Kiyo his "bride". A vampire's "bride" is a female human who will become his only source of blood. Even though Kiyo seems to like Kuroboshi, she gets embarrassed when he tries to **** her blood, which is a problem for Kuroboshi.
Then, Kiyo's childhood friend tries to stop their growing affection, because he is afraid that Kiyo will be tainted by the vampire. Kiyo is then told that if she wants to be with Kuroboshi forever and be his bride, she will have to kiss him. There is one side effect—she might turn into a vampire herself!