Main Charactors
Karin Maaka
Karin is descended from a long line of purebred vampires. However, instead of having to drink blood like normal vampires, Karin's body overproduces blood. Eventually, she reaches a point where she can no longer hold it, and she must bite someone to inject them with her blood, or she suffers from a massive nosebleed. Karin's blood taste is described in the original Japanese as f**ō, which has been translated into English as "misfortune" in the manga and "unhappiness" in the anime. When she bites someone, they are injected with her blood and become more energetic and less unhappy. If Karin goes too long without biting someone, and holds her blood in, she goes into a "berserker"-like state and aggressively seeks a target, attacking the first possible one she can find. Due to her unusual state, Karin can walk safely in sunlight and in many ways is more human than vampire. She is unable to summon familiars, erase human memory, or demonstrate any other vampire traits. This tends to separate her from the rest of her family, as she lives like a human during the day while they live normal vampire lives at night. Her condition worries her family, particularly in that her nosebleeds appear to physically endanger her.
Kenta Usui
Kenta Usui is the first person to have found out Karin's secret. Under Anju's suggestion, the Marker family make him an ally, telling him that if he kept their secret and looked after Karin, they wouldn't erase his memory. Kenta and his mother live in a one room apartment and do not have much money. Consequently Kenta can't afford three meals a day, which means he's often hungry during the middle of the day. Karin, realizing this, begins making him a bento every day.
Kenta works with Karin part-time at Julian restaurant, and gets all the hours he can to support himself and his mother. He dreams of being a model citizen with a family and a good job. Initially, Kenta is considered scary by most people who meet him, since he has rather startling eyes.
Maki Tokitou
Maki is Karin's friend since childhood and classmate, the daughter of a family who runs a bookstore, Toki Books. She is energetic and kindhearted. Maki protected Karin from bullies after Karin's first blood discharge in public caused her to become an object of ridicule and continues to assist her wherever and whenever she may; Maki has set her mobile to play the opening movement of "Also sprach Zarathustra, Op.30" by Richard Strauss whenever Karin rings.
Anju Maaka
Karin Maaka's younger sister, Anju Maaka is a normal vampire who, for much of the series, has yet to reach the onset of her adulthood, and thus is not required to suck the blood of others. Due to her young age, Anju can travel outside when it is cloudy, during dusk, or when she is carrying her parasol to block out the sun. Despite her young age, Anju is quite proficient in the vampire art, and has a group of bat familiar spirits who are able to aid in her watch over Karin. Anju has a collection of many dolls in her room, but her favorite seems to be Boogie, which she carries around almost everywhere she goes.
As Karin is unable to erase human memory, Anju's aid is frequently required after Karin has bitten a human. However, Anju knows that when she matures, Karin will be alone when she is outside during the day, so she persuades Karin's parents to allow Kenta to know about Karin without having his memories erased so that he can look after her in Anju's stead. Anju may seem very emotionless at times, but she also seems to possess quite a temper; she can be very scary if anyone hurts or teases Karin. She is also hurt when Karin attempts to be cheerful over Anju's moving from the light to darkness as she matures.
Boogie (Anju's Doll)
Boogie is Anju's favorite doll and constant companion. Loud and rude, he often speaks up loudly to support Anju's interests. Boogie houses the soul of a serial killer (known as the Stripe Shirt Slasher) who killed 13 victims before his own death. The doll has a fabric knife in his hands, and when his soul escapes the doll, Boogie still attempts to kill people, though being a shadow can only scare them. In the anime adaptation, after Anju becomes a full vampire, Boogie appears to relapse into a normal doll.
Ren Maaka
The older brother of Karin Maaka, Ren is the stereotypical example of a vampire; he seems to suck blood almost mercilessly to fulfill his thirst. Ren sees the act of biting as a metaphor for sexual intercourse, and often commits both acts simultaneously. Attracted to the stress inherent in the blood of women, Ren believes vampires to be superior to humans.
While Ren seems to be wise in the way of the modern vampire, he seems almost ignorant to the subtle humanities of his role. Ren seems to view Karin as a screw-up, not actually because of her blood increasing, but instead because of her lack of ability and willingness to use her vampiric abilities, and her attitude towards humans, which sees humans and vampires as equal. However, on two occasions he has shown feelings for Karin as an older brother, as he was the one who, after spending an evening in the High Street with her, realized that her blood increment was caused by unhappiness. He fights to keep her in episode 24, telling Kenta, 'I won't let you have my sister' although Winner takes the fight and Anju uses her familiars to take Kenta away from the situation and closer to the lake, where Karin is. When Victor appears at the lake, he also shows feelings towards his family as a whole.
Henry Marker
Karin Maaka's father, Henry Marker is a vampire who is portrayed as surprisingly human; he seems to act in a way one might call 'silly.' Despite Karin's anomalies and flaws, he loves her dearly. This is exemplified when Karin first suffered a nosebleed at a human school; Henry braved the sunlight to rescue Karin from the hospital workers, who would have realized she was a vampire upon examination, and is severely burned in the process. Henry suffers normal paternal jealousy when the possibility of love between Karin and Kenta Usui arises. When they moved to Japan, he and Calera kept the English spelling of their last names, while their children chose to use the Japanese romaji spelling.
Calera Marker
Calera Marker is the wife of Henry Marker and the mother of Karin Maaka. Calera seems to have dominant control over the Marker family; she is constantly 'correcting' their opinions with a slap across the face from a slipper. However, there are occasions on which she bows to the will of her husband Henry. Calera seems much more ashamed of Karin than her father and seems to prefer Anju as a daughter. Appearances notwithstanding, Calera truly cares for Karin and worries about her safety even if she is strange for a vampire.
Elda Marker
Elda Marker is the mother of Henry Marker and the paternal grandmother of Karin Maaka. Elda does not show respect for humans and drinks blood as she sees fit, leading the other Marker family members to perceive her as a monster. She is generally loathed by Calera, possibly based on the classic mother vs. daughter-in-law conflicts.
