I will update the character profiles as the story progresses.

Kang Kyungwon (Codename: Yuha): 18 years old. A vampire hunter who lost her memories eight years ago. She was forced to kill her best friend after she was kidnapped by vampires. After that incident, she gave up hunting for three years. She seeks revenge against the one who ordered her death, but instead caused her best friend to be killed as a casualty. After moving to a new town, she starts to find bits and pieces of her mysterious past. There she meets Kim Minkyung, but she has no recollection of her. Kyungwon's anti-vampire weapon is a katana with a jet-black blade and silver t along the edge of the blade. Her sword's affinity is fire, and she produces black-blue flames. Her katana transforms into a silver ring in its dormant state.

Kim Minkyung (Alias: Roa): A woman from Kyungwon's mysterious past. She is a pureblood vampire and is the youngest in the Kim family. A princess in the royal family, she was born to the main branch of the Kim family. She is over 1700 years old, Minkyung spent 800 years asleep and was awake for the last 250 years. She met Kyungwon when she was younger, and is surprised to see her eight years later, but it isn't the same Kyungwon from back then. She ends up falling in love with the vampire hunter.

Yewon (Codename: Yehana): 16 years old. Kyungwon's younger sister, whom she affectionately calls her "sunshine." Choice of weapon is a whip, in its dormant form it becomes a silver bracelet. She used to hunt as a pair with Kyungwon before the older girl gave up hunting. She is normally a bright girl, but when it comes to hunting vampires, she is more serious than ever. 

Im Nayoung: 25 years old. An extremely talented vampire hunter, she known as the "Goddess of Death." She is famous among vampire hunters, and vampires alike. Most vampires who meet her end up dead, hence her nickname. She is one of the few vampire hunters who choose to hunt solo. She is normally icy and aloof, but is caring of her subordinates and family/friends. A candidate to be the next leader of the Hunter's organization ARTEMIS. She dedicates the later part of her life to hunting a pureblood vampire, and seeks to unravel a web of lies with the help of her sister, Yoona and her close friend, Seulgi. She uses a scythe named Shiki, and in it’s portable form it is in the shape of a pen. Her affinity is fire and she produces purple flames. Holds the position of a Captain in the organization.

Kang Seulgi: 26 years old. Originally stationed in Daegu, she looks for clues to unravel a conspiracy, and to get her revenge. She is ordered to stay in the Seoul branch to help out against the level F epidemic. Along with Im Nayoung she is one of the candidates to become the future leader of ARTEMIS, though she is uninterested in the position. Another talented hunter, she trained with Nayoung when they were younger. Her anti-vampire weapon is a long sword with a serated edge. Within the Hunter's Organization, she is a Lieutenant Colonel.

Park Kahi: The cold and pragmatic leader of ARTEMIS. Her goal is for the complete extermination of vampires. 

ARTEMIS: The name of the Hunter's Organization, they also govern the vampire hunters. The main branch and its headquarters is located in Seoul. ARTEMIS is led by President Park Kahi. Its current goal is the complete extermination of the vampire race. Despite the fact that not all hunters agree with this. A council helps determine its course of action, and only high-ranking hunters are allowed on the council. 

Vampire Hunters: Humans who are gifted with the ability to kill vampires, with the aid of an anti-vampire weapon. Their duty is to protect humans, and to hunt down rogue and level-F vampires. They have slightly accelerated healing, are stronger than typical humans, and are faster. Those born into vampire hunter families, start their training at age 6, field training begins around 8-9 years old, and they shadow experienced hunters until they are sent on missions. At age 12, they are usually sent on missions with a supervisor, usually with their other hunter pair if they have one. Hunters typically work in pairs, some even swear an oath to create the Hunter's Bond. Some of the famous vampire hunter families include: The Kang family, Im family, Park family, and Jung family.

Pureblood Vampires: The most defining feature they have is their gold eyes. They are noticibly more stronger than other vampires. They are of the highest rank among the vampires, and they do not have any human ancestry within their family tree—leading their blood to be "pure." They have special abilities, and are truly immortal, they can live forever unless they are killed with an anti-vampire weapon. They can form a sire bond with those they've turned, leading that vampire to be under their complete control. They can also control other vampires below them, the instinct of most vampires is to serve the purebloods. The Kim family is the most famous pureblood family, also known as the Royal Family for being the first pureblood family to exist.

Aristocrat/Noble: They have blue or green eyes. They are known as Level B vampires, they are the second in rank after the purebloods. They have traces of human ancestry within the family tree. They are not as strong as purebloods, but they also have special abilties. They are still able to be compelled by the purebloods, but most of them follow purebloods of their own violation. Some families of nobles have sworn loyalty to only one family of the purebloods. They dedicate their lives to serving the members of the pureblood family, and some will become their personal guard. They turn to dust when they are killed, just like all the vampires below the purebloods. They usually take on the task of eliminating level F-vampires.

Common Vampires: They have red eyes. They were originally human until they were turned, meaning they were not born a vampire. Those who have been bitten and who have gone crazy with their inability to control their bloodlust are deemed "Level F." They do not have any special abilities. Some vampires have given up drinking human blood and instead either drink animal blood, or use blood tablets as a substitute.