Tsukune Aono is the male protagonist of the series who is mistakenly enrolled in Yokai Academy. He almost immediately meets Moka Akashiya, a vampire who takes an interest in him due to the sweet taste of his blood (a running gag in the series involves her catching Tsukune off-guard and biting him on the neck). Fearful for his life and ready to leave the school, it is only his affection for Moka that gets him to continue attending Yokai Academy. Though he has no special powers of his own, he constantly risks his life to protect his friends. Later on, he acquires vampiric abilities, then ghoul-based powers (the latter of which puts his humanity in jeopardy), allowing him to fight toe-to-toe with almost any supernatural foe.
Though ordinary and often cowardly in the beginning, Tsukune's willingness to protect his friends without second thought earns him many new companions and the affection of the girls surrounding him. He is both gentle and understanding, and displays great courage when his friends are threatened. Later in the series, Tsukune is infused with Moka's blood and starts to undergo changes, such as gaining vampire fighting skills when he or one of his friends is threatened. At first, Moka feels responsible for this, but Tsukune says that he doesn't blame her for his transformation.