Kojou Akatsuki (暁 古城, Akatsuki Kojō) is the main protagonist of the story. He is the older brother of Nagisa Akatsuki and the childhood friend of Yuuma Tokoyogi. Although he appears to be a normal high school student studying in Saikai Academy, he is actually the fourth primogenitor; the strongest vampire in existence, an immortal demon thought only to exist in legends. He became a vampire and the fourth progenitor only three months before the beginning of the story. For much of the story, he cannot remember how he became a vampire and gets an intense headache whenever he thinks about it too hard. His vampiric urges surface every time he is sexually aroused, his nose bleeding during these situations, and he can only stop his vampiric urges by drinking blood. At the beginning of the story, Yukina Himeragi is sent from the Lion King Organization to observe him and to eliminate him if he is deemed dangerous.
Appearance
Kojou is 16 years old at the beginning of the story. He has dark silver-blue hair and blue eyes which turn red when he is either aroused or angered. He is usually seen wearing the Saikai Academy school uniform which consists of a white button up shirt and black pants. He also wears a blue under shirt and a white hoodie. Since he is a vampire and tends to avoid daylight, he has fair skin. He has well-toned muscles and a "well-endowed" body.
Personality
Kojou is a kind, empathetic person, who goes out of his way to help others. He is also an intelligent, sly and carefree individual. When angered, Kojou becomes quite fearsome adversary. Kojou has indomitable willpower, supernaturally strong charisma which has attracted the attention of both admirers and allies, allowing him to even befriend his enemies. Kojou is shown to care and worry about his sister a lot. He is however generally oblivious to the romantic feelings that others have of him.
History
Kojou was a normal human until he first met Avrora the 12th Kaleid Blood and became her blood servant, a pseudo vampire. Since then, he spent his daily life with her but those days didn't last long until she ordered him to destroy her and became the fourth primogenitor. In addition, he lost his memories regarding the incident and the days they spent together. However, he later regained some portions of it after fighting Giada, the third primogenitor disguised as Avrora using the No.14 Grimoire in attempt to recover his lost memories. He fully regained his memories alongside Asagi after Yukina performed a ritual on them.
He first met Yuuma when he was trying to retrieve Nagisa's hat which was stuck on a branch at the end of a cliff. He looked for Yuuma at her regular spot where she used to hide and watch both siblings everyday and asked for her help. Without waiting for a respond he quickly grabbed her hand and got back the hat together. However, after they did so Kojou nearly fell off the cliff only to be saved by her, he later thanked her and said that she's pretty strong. A while later after everyone introduced themselves. He first met Motoki and Asagi during middle school.
He first met Avrora at Fairy's Coffin. Kojou used his body to protect his sister and Avrora from the terrorist attack leaving him on the verge of death. Avrora admired his courage and turned Kojou into her blood servant. Avrora ordered him to destroy her alongside "Root" and chose him as the 12 Kaleid Blood's successor.
Plot
Abilities
Despite being laid back, he has repeatedly shown to be extremely intelligent, clever and a quick learner, although these traits are not usually shown because he usually tends to charge without thinking, but he can be impressively logical, observational, deductive & tactical. These traits make him an excellent leader.
Enhanced Vampiric Abilities: He possesses supernatural strength, agility, awareness, speed, senses, regeneration capabilities, endurance and immortality. Being the Fourth Primogenitor, his incredible powers are far above that of most vampires Kojou is absolutely immortal meaning he doesn't age or get sick, & any damage he receives (physical, or spiritual) he will rapidly and recover from, even decaptation or complete incineration.
Familiar Summoning: Kojou has twelve familiars which is a manifestation of his vampire's powers. Initially, these familiars would not fully obey Kojou and would often go on rampage. This is due to the fact that he refuses to drink human blood and thus, they would not acknowledge him as their master. However, he is able to control his familiars and summon them properly once he drinks blood. It is revealed that Kojou is still lacking three familiars inside him, one of them is the 12th that lies inside Nagisa while the 6th and 10th still have their Kaleid Blood bodies. They are currently in Oceanus Grave II under the custody of Dimitrie. Every time Kojou releases new familiar, he says the following chant:
I, Akatsuki Kojou, successor to the blood of "Kaleid Blood", now release your constraints. Come ....(number and name of familiar)
"カレイドブラッド"の血脈を継ぎし者暁古城が汝の枷を解き放つ疾く在れ ...(number and name of familiar)
"Kareidoburaddo" no ketsumyaku o tsugishi mono, Akatsuki Kojō ga, nanji no kase o tokihanatsu. kyagare ... (number and name of familiar)
| Name | Description | Image |
|---|---|---|
| 1st Familiar - Aries
Prote - Mesarthim-Adamas / The Divine Sheep of Adamantine |
The medium for this familiar is Kanon. It is a sheep with more than ten thousand diamonds covering it's entire body. This familiar is capable to manipulate diamonds. It is able to spread or scatter them like shotguns and form shields reflecting various attacks/abilities making it well balanced on offense and defense. The diamonds are strong enough to block Al-Meissa-Mercury's dimension eating capabilities. | 
|
| 2nd Familiar - Taurus
Deutera - Cortauri-Sucinum / The Ox Headed King Of Amber |
Amber colored Minotaur armed with an axe that controls land and lava / Medium for this familiar is Glenda. One of the three familiars Kojou does not yet possess. |
|
| 3rd Familiar - Gemini
Tritos - Al-Meissa-Mercury / The Serpentine Dragon of Mercury |
This is the third familiar shown in the series. Kojou took control of it after drinking both Yukina's and La Folia's blood. It is a double-headed serpent dragon that is also called the Dimension Eater. This familiar is capable of reality warping / eating void and space. It is able to withstand angelic powers. It's mouth can devour anything that acts like a black hole. | |
| 4th Familiar - Cancer
Tetartos - Natra-Cinereus / The Carapace of Silver Mist |
The medium for this familiar is Sayaka and Yuuma. It is a silver crayfish with blue flames on it's claws. This familiar is capable to render anything ethereal by producing mists. Due to the fourth primogenitor's strength, the mists are able to cover the whole island without any difficulties. In episode 19, it is said that this familiar was only half-materialized as a wound on Kojou's chest (when Himeragi stabbed Kojou). The mists are strong enough to ward off reality warping. | 
|
| 5th Familiar - Leo
Pemptos - Regulus-Aurum / The Lion of Gold |
This is the first familiar shown in the series and is commonly used by Kojou. Kojou took control of it after he drank Yukina's blood. It is a lion-like familiar having glowing red eyes and has a lightning-like mane. This familiar is capable to produce and manipulate lightning. Kojou is able to manipulate the lightning to create a force field around him. The lightning is strong enough to weaken a divine vibration barrier. It can obliterate several hundreds of kilometers by just releasing it's powers. | |
| 6th Familiar - Virgo
Hektos - ? / ??? |
Not revealed yet. |
|
| 7th Familiar - Libra
Hebdomos - Kiffa-Ater / The Black Sword of Abraded Night |
The medium for this familiar is Yukina and Sayaka. It is an intelligent-type weapon, a gigantic demon sword over 100 meters in length. This trident-like sword is capable to manipulate gravity. It can obliterate few dozens of kilometers if swung from a high altitude. |
|
| 8th Familiar - Scorpio
Ogdoos - ? / The Manticore of Flames |
It is a man-eating manticore that controls fire. |
|
| 9th Familiar - Sagittarius
Enatos - Al-Nasl-Minium / The Bicorn of Deep Crimson |
This is the second familiar shown in the series. Kojou took control of it after he drank Sayaka's blood. It is a bicorn-like familiar having glowing purple eyes, black-colored skin, purple fire-like mane and has glowing plate-shaped armor floating around its neck. This familiar is capable to produce and manipulate sound. It is able to create sound quake and waves. It can tear molecules at an atomic scale by emitting high-frequency vibrations from it's entire body. | |
| 10th Familiar - Capricornus
Dekatos - Dabih-Crystallus / The Goat of Glinting Eyes |
Mind Control / One of the three familiars Kojou does not yet possess. |
|
| 11th Familiar - Aquarius
Hendekatos - Sadalmelik-Albus / The Water Spirit of White Steel |
Avrora awakened this familiar by force while in Nagisa's body and subsided by, then gained control of it after drinking Yukina's blood. It is a combination of an undine and a snake. This familiar is capable to revert phenomenon to it's original state which is nothingness. Due to this ability, Kojou is able to recover from any kind of injury including decapitation as shown in the series. It is able to to erase conceptual existence. | |
| 12th Familiar - Pisces
Dodekatos / Alrescha-Glacies / The Bewitching Princess of Azure Ice |
It is a combination of a siren and a mermaid. This familiar is capable to decrease temperature below absolute zero to which was first seen with his sister Nagisa, who has a part of Avrora currently living inside her. One of the three familiars Kojou does not yet possess. |
Gallery
Trivia
- Kojou's hair was originally color black but was later on changed into gray.