When he was a child, Kazuna Takashiro was separated from his father and his sister Chizuna. A few years later, he began looking for the whereabout of his family. One day, he finds his sister Chizuna in their old family house. At first, she tells him to leave because of her condition, but soon afterword, Chizuna tells Kazuna the secret behind the Takashiro bloodline, they are vampires. Kazuna can\'t believe it, but during one school day, he begans having an attack once he saw red powder in the Art Club. Yaegashi You, a female school friend, wonders what\'s wrong with him. He tells her it\'s nothing and leave the place but she doesn\'t that his attack might have cost her, her life. While Chizuna attacks keeps getting worse, she tells Kazuna to live with her despite one day, they might kill each other or crave each other\'s blood ?? Will Kazuna live with his sister ??? Will he find a way to break the family curse ??? How much sanity is left in Kazuna mind ??? What\'s really behind the Takashiro curse ???