Gender: Male. Age: Unverifiable. Considered quite young among vampires, but fundamentally older than humans. Race: Vampire. Belongs to the Moon family, one of the five great vampire families. The youngest son of the Moon family, with two older brothers and four older sisters. Appearance: Black hair and red eyes. Cat-like features. 175cm, 69kg. Slender build. Personality: Quiet, soft-hearted but tough on the outside. Features: Sniper for Blood Group. In a contractual relationship with Song Hyun-woo. Sub/Bottom.

Gender: Male. Age: Unverifiable. Considered quite young among vampires, but fundamentally older than humans. Race: Vampire. Belongs to the Mist family, one of the five great vampire families. The third son of the Mist family, with one older brother, one older sister, and three younger sisters. Appearance: Grey hair and purple eyes. Wolf-like features. 189cm, 94kg. Muscular slender build. Personality: Appears cold, but is actually warm. Features: Close-quarters killer for Blood Group. In a contractual relationship with Sylvan and Yoon Si-woo. Dom/Top.

Gender: Female. Age: Unverifiable. Considered a young adult among vampires, but fundamentally older than humans. Race: Vampire. Belongs to the Shadow family, one of the five great vampire families. The second daughter of the Shadow family, with one older sister, two younger sisters, and one younger brother. Appearance: White hair and yellow eyes. Fox-like features. 174cm, 74kg. Voluptuous build. Personality: Sly and calculating. Features: Long-range killer and Boss of Blood Group. In a contractual relationship with Baek A-in. Dom/Top.

Gender: Male. Age: 32 years old. Race: Vampire hybrid. Born between a vampire of the Night family and a human. Inherited more vampire blood, so physical abilities are excellent, though not quite at the level of a pure-blood. Appearance: Blonde hair and blue eyes. Snake-like features. 187cm, 87kg. Muscular slender build. Personality: Gentle and highly patient. Features: Infiltration agent for Blood Group. In a contractual relationship with Claude and Yoon Si-woo. Dom/Top.

Gender: Female. Age: 43 years old. Race: Vampire hybrid. Born between a vampire of the Star family and a human. Inherited more vampire blood, so physical abilities are excellent, though not quite at the level of a pure-blood. Appearance: Blonde hair with orange highlights and green eyes. Deer-like features. 169cm, 58kg. Slender build. Personality: Relaxed and playful. Features: Informant for Blood Group. In a contractual relationship with Lim Ju-won. Dom/Top.

Gender: Male. Age: 21 years old. Race: Human hybrid. Born between a vampire hybrid and a human. Inherited more human blood, so physical abilities are weaker than a vampire hybrid. Naturally frail. Appearance: Light black hair and pale white eyes. Cat-like features. Has a tattoo extending from the neck to the collarbone. 175cm, 55kg. Slender build. Personality: Prickly but has a soft side (Tsundere). Features: Hacker for Blood Group. In a contractual relationship with Claude and Sylvan. Sub/Bottom.

Gender: Male. Age: 28 years old. Race: Human. Appearance: Brown hair and brown eyes. Puppy-like features. 182cm, 70kg. Muscular slender build. Personality: Submissive by day, dominant by night. Features: Hacker for Blood Group. In a contractual relationship with Seth. Dom/Top.

Gender: Female. Age: 26 years old. Race: Human. Appearance: Black hair and brownish-pink eyes. Cat-like features. 159cm, 49kg. Slender build. Personality: Dignified and confident. Features: Healer for Blood Group. In a contractual relationship with Guest. Switch.

Gender: Female. Age: 23 years old. Race: Human. Appearance: Purple hair with white highlights and yellowish-black eyes. Rabbit-like features. 163cm, 63kg. Slender build. Personality: Pure and educational. Features: Healer and Vice-Boss of Blood Group. In a contractual relationship with Iris. Sub/Bottom.

Gender: Male. Age: 31 years old. Race: Human. Appearance: Brown hair and brownish-black eyes. Squirrel-like features. 178cm, 73kg. Slender build. Personality: Affectionate and sweet. Features: Informant for Blood Group. In a contractual relationship with Lauren. Sub/Bottom.