Ko Yamori
Voiced by: Gen Satou
Ko is a 14-year-old junior high student whose growing dissatisfaction with life drives him to wander the streets at night. He hopes to escape his humanity by becoming a vampire through loving Nazuna. Gradually, he gains the ability to enter a half-vampire state, first triggered by emotional turmoil or physical blood loss, including minor wounds. Anko supplies him with an ear-piercing kit to control these transformations, theorizing that frequent use or stronger romantic attachment could complete his transition into a full vampire.

Nazuna Nanakusa
Voiced by: Sora Amamiya
Nazuna is a unique born vampire who meets Ko during his nightly walks. A playful but socially awkward figure, she enjoys teasing him, crude humor, and beer. Her exact age is unknown (estimated 30–40 years), and she feels insecure about not fitting traditional vampire stereotypes. As the hybrid offspring of a vampire mother and human father, she matured rapidly while retaining childlike traits, making her an outcast among turned vampires. Her preserved umbilical cord is her sole weakness.

Akira Asai
Voiced by: Yumiri Hanamori
Ko’s childhood friend, who lives in the same apartment complex as him. She attempts to try and convince him to return to school, but also, reluctantly, is supportive of his dream of becoming a vampire. She treasures her relationship with Ko and Mahiru.

Seri Kikyo
Voiced by: Haruka Tomatsu
A flirtatious vampire who resembles a gyaru. She approaches Ko when she hears that Nazuna is spending the night with a human where she attempts to suck his blood, until she is stopped by Nazuna. The two do not get along well, as she questions why Nazuna is spending so much time with Ko while not having turned him yet.

Nico Hirata
Voiced by: Eri Kitamura
A vampire who doubles as a teacher who teaches night classes. She is not as accepting of Ko in her first encounter with him, but becomes willing to let him stay with Nazuna so long as he fulfills his intentions on becoming a vampire and Nazuna continues to suck his blood.

Kabura Honda
Voiced by: Shizuka Itou
A vampire who wears elegant dresses. She works as a nurse in a hospital and she is Nazuna’s adoptive mother. She is hopelessly in love with Nazuna’s mother, Haru Nanakusa, the woman who turned her, and due to how similar Nazuna looks to her mother, she has a tendency to act like an overbearing and doting parental figure, while also venting her own feelings toward Haru at Nazuna.

Midori Kohakobe
Voiced by: Naomi ouzora
A long-sleeved shirt-wearing vampire who works in a maid cafe. She is very aware of her good looks leading her to seem a little self-absorbed in some situations.

Hatsuka Suzushiro
Voiced by: Azumi Waki
A male vampire who appears feminine because of his slender body, shoulder-length hair, cute face, and choice of clothing.