Tsukune Aono is a normal high school freshman who is unable to get into any private school, due to his dismal grades. The only school he is finally accepted into turns out to be a secret school for supernatural monsters and mythical creatures (yōkai), who are disguised as humans. He quickly becomes friends with the beautiful Moka Akashiya, who turns out to be a vampire attracted to the sweet taste of his blood (and Tsukune's only, it turns out). While at first Moka was upset upon discovering that Tsukune was actually a human, she realizes that he's the first real friend she had ever made. Tsukune quickly realizes his admission into a monster school must have been a mistake and fears for his life.