Kojou Akatsuki

Kojou Akatsuki ( Akatsuki Kojō) is the male 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 primogenitor 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 when he attempts to. Yukina Himeragiis sent from the Lion King Organization to observe him and to eliminate him if he is deemed dangerous.

Personality
In his human side, 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 due to his strong siscon nature.

In his vampire side, he is an unintentional pervert who bite girls to drink their blood while in sexual.