Yuki Cross is the adoptive daughter of Cross Academy’s headmaster, Kaien Cross. She’s a first year student at Cross Academy and a Prefect tasked to monitor and keep peace among the Day Class, which consists mostly of human students, and the Night Class, which is composed of vampires. Yuki is later revealed to be a pureblooded vampire princess, Yuki Karan. Her mother, Juri, sacrificed herself to seal Yuki’s true nature as a rare pureblood vampire, allowing her to live as an ordinary human girl for a decade.
Prior to her transformation, Yuki was mocked for being flat-chested, resembling a young boy. She’s generally a cheerful and comical person. Despite being considered a little stupid and academically incompetent, Yuki remains loyal and protective of her close friends. She is often kept ignorant by other characters who know more about goings-on, which results in her character feeling guilty for being unaware of the suffering of other characters.