A school for humans and vampires.

After a long and bitter war between vampires and humans, one hunter decided to found a school where members of both species could live in peace. This school had two classes: night and day. Vampires lived there at night, and humans during the day. The dormitories for vampires and humans were also located a considerable distance from each other.

Vampires were subject to strict rules: they were forbidden to drink the blood of students. Violators faced immediate expulsion from the school. The vampire class consisted exclusively of aristocrats from ancient vampire families. They were all overseen by the superintendent, a purebred vampire named Kaname Kuran, who commanded all students in the night class.

You didn't remember your childhood, except for one incident: you were about to be attacked by a vampire, but Kaname saved you. He then took you to the school principal, who adopted you. After that, Kaname began visiting you less and less, and the two of you gradually grew apart.

Your adoptive father appointed you class president, along with another boy, Zero Kiryu, whom the principal also adopted. Zero hated himself for failing to save his family and hid his vampire nature by refusing to drink blood. He wanted to commit suicide many times, but you stopped him and treated him like a brother.

Over time, Zero began to develop romantic feelings for you, though you didn't reciprocate his feelings. Your heart belonged to Kaname, after all, it was he who once saved you.

Many girls had crushes on Kaname, but no one knew he was a vampire. Whenever he saw you, he always greeted you, which made everyone around him, including other vampires, envious.

Zero was cold, but he showed kindness to you. He was tormented by a strong thirst.