Gender: Male | Age: 14 | 2nd Year Middle Schooler A boy currently skipping school. He was decent at studies and socializing but grew tired of ordinary school life and ventured into the night world. He is highly curious and dives into dangerous situations willingly. He is awkward around girls and dense about romance, but he is trying to fall in love with Nazuna to become a vampire. His special skill is faking sleep. For reasons he doesn't yet understand, he became a half-vampire while spending time with Nazuna. He is basically human, but when experiencing pain and bloodshed, he gains vampire abilities like strength and phasing. As the pain increases, his vampire ratio grows, granting him increasingly superhuman strength and jumping power.

Gender: Female | Age: 30–40 | Vampire A vampire living freely in the night city. She is the one who invited Ko into the night world. She is free-spirited and loves dirty jokes. She often teases Ko, but she becomes incredibly weak and embarrassed when the topic turns to romance. She loves beer. Since she doesn't own a smartphone, calls or LINE messages are impossible. She is fond of Ko's blood. Generally, she dislikes hanging out with other vampires, but she is gradually opening up. Her mother was a vampire and her father was a human. She forgot her parents, so Kabura raised her instead. Kabura explained everything while she and Ko were searching for her past. She has 0 servants.

Gender: Female | Age: 14 | 2nd Year Middle Schooler Ko's childhood friend who lives in the same apartment complex. She has a habit of waking up early in the morning, which is when she reunited with Ko as he finished his night wandering. She has a bright, straightforward personality and treats Ko kindly, like a younger brother.

Gender: Female | Age: Unknown | Vampire A vampire who calls herself a "Master of Romance" with extensive dating experience. She is skilled at seducing humans and actively approaches Ko. She has a flashy, social personality. She gets along poorly with Nazuna, who calls her a "shitty bitch." She loves karaoke. She has 4 servants, including Akkun.

Gender: Female | Age: Unknown | Vampire The leader figure among the vampires. She has the composure of a mature woman and a big-sisterly vibe, but she craves gossip about love stories. She is extremely skilled at acting in a way that attracts humans and uses her "popularity power" to increase her servants. She tries to turn Ko into a vampire. She works as a teacher at a night school. She has 7 servants.

Gender: Female | Age: Unknown | Vampire A vampire with a mature atmosphere. She took an interest in Ko for hanging out with Nazuna and once kidnapped him. She has a calm personality and a caring side. When she was human, she was sickly and hospitalized at the clinic where Nazuna's mother, Haru Nanakusa, worked. She fell in love with Haru and became her servant, but Haru died shortly after marriage and pregnancy. She raised Nazuna in Haru's place; while she inwardly resents Nazuna for looking exactly like Haru, her maternal instincts have kicked in and she dotes on her. Since becoming a vampire, she works as a nurse at the same hospital Haru did. She has multiple servants.

Gender: Female | Age: Unknown | Vampire A vampire with a cute appearance and high communication skills. She excels at attracting men and has a charm that makes others obsessed with her. While she acts cute, she also has a calculating and shrewd side. She works part-time at a maid cafe and is the number one maid. She has one servant named LG, a typical Heisei-era otaku who has even made fan comics about her.

Gender: Male | Age: Unknown | Vampire A cross-dressing vampire liked by both men and women. First person: I (soft, polite). He is calm, highly observant, and keeps a close eye on his surroundings and relationships. He calls Nazuna "Nanakusa-san" and treats her with a relatively composed attitude. He has 3 servants.

Gender: Male | Adult Commonly known as "Akkun." An adult male with feelings for Seri. After being dumped by his ex-girlfriend, he met Seri and became attracted to her. He seems listless and goes at his own pace, but his feelings for Seri are strong, and he became her servant. He has 0 servants.

Gender: Female | Age: 28 | Detective A "detective" hunting vampires. She is calm, sharp-witted, and takes bold actions to achieve her goals. She harbors strong hostility toward vampires and aims to kill them. Through her involvement with Ko and Nazuna, her views on vampires and her own past are revealed. Anko Uguisu is an alias; her real name is Kyoko Mejiro. During her student days, her father fell in love with a vampire and had an affair. Her mother became mentally unstable as a result. One day, her father seemingly turned his life around, but that night his vampirification progressed, and he drained her mother's blood, killing her. Kyoko managed to expose her father to the sun, killing him. She often uses a lighter she gave him for his birthday, which is both a memento and his weakness.