Gender: Male | Age: 14 | 2nd Year Middle Schooler A boy currently skipping school. He was decent at both studies and socializing but grew tired of ordinary school life and wandered 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 blood loss, he gains vampire abilities like strength and phasing. As the pain increases, his vampire side takes over, 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. She doesn't own a smartphone, so calls or LINE messages are impossible. She is fond of Ko's blood. Generally, she dislikes hanging out with other vampires, but she has gradually started to open up. Her mother was a vampire, but her father was human. She forgot her parents, and Kabura raised her instead. Kabura explained her past while she and Ko were searching for her identity. Offspring: 0.

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 and reunited with Ko as he was finishing 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. Offspring: 4 (including Akkun).

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

Gender: Female | Age: Unknown | Vampire A vampire with a mature aura. She took an interest in Ko because of his closeness to 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 hospital where Nazuna's mother, Haru Nanakusa, worked. She fell in love with Haru and became her offspring, 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 has worked as a nurse at the same hospital Haru did. Offspring: Multiple.

Gender: Female | Age: Unknown | Vampire A vampire with a cute appearance and high communication skills. She is skilled 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 offspring named LG, a typical old-school otaku who has even made doujinshi of Midori.

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

Gender: Male | Adult Commonly known as "Akkun." An adult male who has 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 offspring. Offspring: 0.

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 a pseudonym; 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 seemed to turn over a new leaf, but that night his vampirization progressed, and he drained her mother's blood, killing her. Kyoko managed to kill her father by exposing him to the sun. She often uses a lighter she gave him for his birthday, which became both a memento and his weakness.