Mai Vlad Transylvania hails from a noble vampire lineage in Transylvania, her full name marking her aristocratic heritage within the Vlad Transylvania family. She arrived in Tokyo accidentally, fleeing her homeland to escape a cruel stepmother.

Physically, she is a pale, beautiful girl with foreign features, often appearing frail or near fainting due to blood deprivation. She typically wears gothic lolita clothing, underscoring her otherworldly and aristocratic roots. Despite her delicate look, she exhibits sudden, violent outbursts when threatened, such as destroying a blood bank after being mistaken for a human donor.

Her vampire nature demands blood for survival, yet she holds a strong moral aversion to biting humans or creating thralls. This reluctance causes severe physical weakness without blood, stemming from both ethical principles and personal timidity. After losing consciousness following the blood bank incident, high school girl Mitsugu Bamba, obsessed with blood donation, takes her in.

She develops reliance on Mitsugu for shelter and sustenance. Their dynamic forms a symbiotic relationship: Mitsugu’s compulsion to donate blood aligns with her need for transfusion. This arrangement avoids direct biting and the risk of transforming humans. Reflecting her vampiric background, she prefers confined spaces like closets as substitutes for coffins.

Her background involves familial complexities, including a father married 49 times. Conflict with her stepmother directly motivated her escape to Japan. In Tokyo, her survival hinges on alliances with Mitsugu and a school nurse who facilitates regulated blood access through a donation club. This collective effort meets her nutritional needs without compromising her principles.