Our heroine Komori Yui has been dumped by her priest father, told that he’s gone off to do work alone and can’t take her with him. Instead he tells her to go live in the house of an old acquaintance of his – but that house just happens to be filled with 6 RICH vampire brothers. Of course they’re not just your average blood suckers – they all have major psychological issues! Their father is a manslut vampire who loves the ladies so he knocked up 3 of them to have 6 kids currently ranging from ages 17 – 19. So now Yui has to live with these wackos and she tells them that she’ll be the one to decide who gets to suck her blood. However, as she spends more time being their therapist, she discovers a shocking secret inside her body.