Pureblood

Purebloods (純血種, Junketsushu) are the highest rank among vampires classed as Level A (Aクラス, A Kurasu, lit. "A Class"). They are "pure" vampires without any human ancestry, and can trace their lineage back to the original vampire progenitors.

Purebloods all possess a series of unique powers, often exclusive only to the certain Pureblood or Pureblood family.

There are currently only seven Pureblood families: Kuran, Hio, Hanadagi, Toma, Shirabuki, Ouri, and Shoto.

Outline
A very long time ago, when the human race was on the verge of extinction the first vampires emerged. These first vampires, known as Purebloods, appeared. Purebloods are those who have not bred with humans, thus keeping their vampire blood pure. Some Purebloods breed with Humans producing weaker vampires which have came to be known as the Noble vampires. Most vampires have some human blood in them, but a Pureblood vampire does not. Purebloods, like all vampires are sensitive to the sun as it only hurts their eyes and can get suburned easily.

War broke out between the Purebloods and the Humans at some point a long time ago. In order to defend themselves against vampires, some humans ate an ancestor's flesh, creating the vampire hunters which granted them the power and strength to kill vampires. This includes anti-vampire magic and weapons. Therefore all vampire hunters have vampire blood in them but not to the extent that they are classified as vampires, thus they do not benefit from a vampires longevity and thirst for blood. The vampire hunters protect the Human race from the vampires.

During the war, the Pureblood population greatly diminished. Many Purebloods drank the blood of humans during this time thus creating Level E vampires to increase the vampire population. Consequently, there are few Purebloods today.

Powers
The full extent of their powers are only known amongst their Pureblood companions. Their true powers remain a mystery. They have ethereal beauty of the Purebloods. They are immortal, meaning they live forever unless an anti-vampire weapon is used to cut off their heads or pierce their hearts. Any other injury is healable, including having one's head cut off or blown to pieces, if a Pureblood uses the blood of another Pureblood to heal them. When a Pureblood vampire is killed, their bodies slowly disperse into small sparkles before shattering into shards of glass.

It is heavily implied that each vampire has a unique power such as Rido Kuran's ability to manipulate his blood or Shizuka's control over plants. Their blood is highly prized and many have attempted to drink their blood, this includes both humans and Noble vampires. The blood of a Pureblood can give vampires new powers. Aside from the standard powers shown by other vampires, Purebloods have also demonstrated the following:
 * They can form shadow puppets/spies using parts of their flesh which are capable of shape shifting.
 * They can transform parts of themselves into animals.
 * Purebloods can create familiars of any form they choose, use their powers and control them.
 * Powers to perform spells to seal off the vampire side of vampires, thus making them a normal human. The spell also erases all of his/her memories of being a vampire. However this spell comes at the price of their life. (The vampire converted to human, eventually must return to his/her true nature, if not, he/she descends into madness. However, this was only in Yuki's case as Isaya said his son died human).
 * Ability to control lower vampires physically.
 * Ability to put vampires and humans to sleep for a short time.
 * Erasing Memories and can control elements.
 * Telekinesis and can cast spells.
 * Morph the flesh and bodies of others transforming them.
 * Ability to possess the bodies of other vampires.
 * They can also put themselves to sleep for a very long time, even hundreds of years, and be resurrected through a blood sacrifice.
 * Purebloods can transform themselves into the form of a baby and grow into their body.
 * Purebloods can become each other's masters if one is awakened by another from slumber.
 * Enhanced sense of smell.
 * Ehanced strength, speed, and stamina.
 * Enhaced durability, agility, and senses.
 * They can feel and see memories of others by drinking their blood.
 * Their blood can heal human illnesses and give them a small amount of strength. (But for a human to drink pureblood's blood, might die due to their blood being highly poisonous to them).
 * Ability to turn humans into vampires and retain complete control over them by becoming their master, rendering the vampire unable to kill them. The blood of their master will also prevent an ex-human from becoming a Level E vampire.

The Kurans are unique among Purebloods, as some members of the family possess and display the ability to handle anti-vampire weapons. Juri Kuran, Yuki Kuran, Kaname Kuran (although he can hold such weapons, it does harm him) and Rido Kuran have demonstrated this ability.

Relationships between Purebloods
Purebloods tend to not show emotion (Yuki Kuran is an exception to this as she had lived as human, and thus doesn't want to bottle up her feelings) and are wary of other Purebloods. Kaname Kuran tells Yuki Kuran about the seven Purebloods families and attacks Shizuki Toma when he harmed Yuki. Juri Kuran guarded Isaya Shoto's home for many years. Ai Kuran ignores letters from Pureblood families. Kaname Kuran murders most of the Pureblood vampires as it was The Hooded Woman's wish to have all the Purebloods to be destroyed.

The Pureblood nature is an everlasting quest for power. (Rido Kuran awoken his ancestor Kaname, to gain more power). By killing and drinking the blood of another Pureblood, they can absorb their power. However, this is a great taboo and is said to summon a sinister future upon that Pureblood, unless it is their lover. Similar to other vampires, a Pureblood's blood thirst can only be quenched by the blood of their loved one. Since Purebloods live for eternity, losing their loved one is much more devastating for them.

It is also common practice for Pureblood siblings to marry each other to preserve their thick blood. Purebloods can also marry another Pureblood, such as Rido Kuran and Shizuka Hio. For example, the Kuran family, who are at the core of the vampire world. Purebloods are the monarchy of the vampire race with the Kuran family serving as the Queens and Kings.

Relationships between other vampires
Relations between the Purebloods and the Nobles are mixed. Noble vampires who are Pro-Monarchy have a strong sense of loyalty to Purebloods as seen by Aido who refers to Kaname as "Kaname-sama" (Respectful and formal Japanese term) and always protects Yuki. It is very important for Purebloods to continue the vampire race, therefore many Noble children are put forward as potential wives or husbands. As opposed to other vampires who are Pro-Vampire Council view the Purebloods as a threat because of their great power; for example Asato Ichijo wanted to rid the world of Purebloods because they have the power to absolutely control lesser vampires will. However, no matter what a vampire's political views are, they all have a seemingly instinctual fear and awe for Purebloods. The Purebloods and the Vampire Council also work together in order to maintain order in the vampire society by keeping watch over Level Ds and exterminating Level Es.

As shown by the timeskip to Ai's toddler days, its shown Purebloods are revered to such an extent that they find it utterly unacceptable for them to be with with a non-Pureblood. In Yuki's case it was worse because Zero was a vampire hunter. Until Yuki spread word that trying to kill Zero was effectively suicide, Zero kept having to kill servants of Aristocrats that went after him. Even after the death threat, 50 years later, vampires still despised the idea of Yuki and Zero being together. As child growing up Ai Kuran was aware of the vampires despising their relationship.

List of Pureblood Vampires
The Kuran family
 * Kaname Kuran
 * The Last Kuran King
 * Rido Kuran
 * Haruka Kuran
 * Juri Kuran
 * Kaname Kuran (II)
 * Yuki Kuran
 * Ai Kuran

The Hio Family
 * Shizuka Hio
 * Unknown Male
 * Hio family

The Shirabuki Family
 * Sara Shirabuki

The Shoto Family
 * Isaya Shoto

The Ori Family
 * Ori (Lord)

The Toma Family
 * Shizuku Toma
 * Unknown Female

The Hanadagi Family
 * Hanadagi (Lord)
 * Hanadagi family

Trivia

 * Given Purebloods usually marry their siblings and have produced offspring without problem for centuries, they obviously lack the human weakness of needing a versatile gene pool.
 * While purebloods originally stop aging in their mid-twenties, putting themselves into slumber can alternate their age.
 * When Purebloods go into slumber, they sleep in a coffin. While purebloods sleep for a long time and thirst for blood, for that time that they put themselves to sleep in, their body will become dessicated.
 * By the time Ai decides to slumber a long time, it seems technology had advanced to create coffins that preseve Purebloods as they are; this is likely as there are numerous tube-like things attached to the bed Ai slept on.
 * Purebloods pregnancy can last 2 to 5 years and can increase their thirst for human blood. When purebloods become pregnant they stay away from humans to prevent feeding from them.
 * Pureblood vampire children do not drink blood until they have their fangs. Like all vampires, young pureblood children take energy until they have to drink blood. When purebloods gets their fangs they have to stay inside their home until they gain control of their impulse to drink blood.
 * Pureblood's blood is desired more than the blood of human children and the blood of their beloved.
 * Purebloods, similar to their Ancestor are the progenitors of the vampire race, with Kaname Kuran being the ancestor and head of the kuran family.
 * When purebloods crave blood, they will feel a burning pain in their throat or use their powers their eyes glow red. Purebloods can quench their thirst for blood through blood tablets and transfusion blood bags.
 * Besides turning into a vampire, when a pureblood bites a human, the human will die from blood loss or poison. While pureblood blood is very powerful, it can be dangerous to vampires and humans.
 * When a pureblood is killed, a fragment of them, their existence, is still alive.