Yuuki Cross/Yuuki Kuran (黒主 優姫 Kurosu Yūki/Kuran Yūki, 玖蘭 優姫) is the adoptive daughter of the headmaster of Cross Academy, Kaien Cross and a school guardian. Ten years prior to the start of the series, Yuuki was rescued from a vampire attack by another vampire a pureblood, Kaname Kuran. She lost all memory of her life from before the attack, and was adopted by Headmaster Cross. After Zero's vampire nature is revealed, she begins giving him her blood to drink, hoping to halt the degradation of his human nature. However, Yuuki loves Kaname, who has always been protecting her and has been by her side during her childhood as a vampire. Yuuki's powers are unknown. When Rido Kuran and his Clan of followers resurfaces at Cross Academy, Yuuki's memories were unlocked after she was re-awakened, revealing that she was actually a pureblood vampire, both Kaname's sister and his fiancée.The revelation of her pureblood status caused a deep rift between Zero and Yuuki. Yuuki now plays the role of a pureblood princess and has approached other purebloods offering her services to any suicidal purebloods. Though Yuuki has now realized that she in fact loves Zero as well, she has decided to stay with Kaname.