A seemingly normal high school girl with a crazy family and a big secret. From the first day on in school, she seems to have developed a huge crush on Makabe, whom she sit next to in class. In the first episode it turns out Ranze does have more of her parents genes than they expected: after getting in a frustrating fight with Yoko, a girl in her class who self-proclaimed to be her love rival, she unexpectedly bites her. After this, she also transforms into the person she has bitten. She can only return to her normal self when she sneezes. When she will become an adult, she has the right to enter the world of Akatsuki. There, her fiancé (whom she has never seen before) will be waiting for her. To accomplish this she only has to remember two things: she may never tell anyone about her parent's true identities, and much worse: she may never fall in love with a human boy.
