Nazuna Nanakusa is a vampire with a youthful appearance despite her true age. She possesses pale skin, light purple hair styled into two ring-shaped braids, and distinctive blue eyes featuring concentric rings in the irises. Her typical attire includes a large cloak over a revealing black leather crop top, denim shorts, and thigh-high boots. Though physically petite, standing only slightly taller than a middle school boy, she wields significant vampiric strength. Created via an experiment involving vampire blood, Nazuna was raised by Kabura Honda following her human parents' death. Her early vampire existence was solitary and gloomy, surviving by feeding on homeless or intoxicated individuals found in public spaces while lacking basic worldly knowledge. Her personality shifted significantly after meeting Kyouko Mejiro, a human detective initially known as Anko Uguisu, who became Nazuna's first friend and shaped her relaxed demeanor. Typically laid-back and approachable, Nazuna enjoys nighttime activities like city exploration and socializing with fellow night enthusiasts. She spends considerable time playing retro video games and consuming alcohol, leading a monotonous life despite presenting herself as a nightlife expert. Her immaturity frequently surfaces through blunt remarks, crude humor, and casual threats of violence. She openly discusses sexual topics but recoils with intense embarrassment to romantic expressions, particularly the word "love." As a vampire, Nazuna feeds by helping insomniacs fall asleep before drinking their blood, operating a "snooze shop" for this purpose. She initially shows no interest in creating vampire underlings and actively avoids popularity. Her blood-sucking arrangement with Kou Yamori, a middle school boy she met at night, forms their relationship's foundation. Their initial agreement allowed her to drink his blood while permitting his romantic pursuit. Over time, she grows protective of Kou, risking her life to defend him and becoming agitated when other vampires target him. She develops genuine romantic feelings, confessing them to others but hesitating to tell Kou directly, fearing such emotions could trigger her transformation back into a human and accelerate aging. Nazuna's character evolves through key conflicts. Confronting Kyouko, who harbored vampire resentment, Nazuna spared her life despite antagonism. This culminated in Kyouko's attempted suicide and Kou emerging as a half-vampire, leading to their reconciliation. Later, during events in Hokkaido involving Kou's friend Mahiru Seki, Nazuna supported Kou with allies, though the aftermath strained her relationship with him, particularly after Mahiru's death. Her romantic feelings intensify, causing jealousy over Kou's interactions with other girls and internal conflict about distancing herself to protect him. Professionally, Nazuna works as a massage therapist with human anatomy expertise, though her approach lacks professionalism. She later takes a job at the maid cafe "Vamp" for its higher salary and post-work beer. Her possessions reflect outdated tastes, including retro gaming consoles and an older model cellphone.