Takahashi Tetsuo, a biology teacher at Shizaki High School, has been fascinated with "demi-humans," beings with characteristics that differ just slightly from humans, since he was in college. He wishes he could have a chance to talk with one, but since the demi-human population is fairly low, he's never even met one. But then the school gains a new math teacher, Satou Sakie... who happens to be a succubus.
In a way, sucking blood is an 
expression of sexual desire.
من ناحية معيّنة، مصّ الدّماء 
.هو تعبير عن الرّغبة الجنسيّة
Irgendwie ist das Blutsaugen
eine Art Ausdruck sexuellen Verlangens.
Así que beber sangre
es una expresión de deseo sexual
Así que beber sangre
es una expresión de deseo sexual
Sucer le sang de quelqu’un,
ça a un côté sexuel,
Mi stai dicendo che succhiare sangue
è l'espressione di un desiderio sessuale,
De certa maneira, chupar o sangue
 é uma expressão de desejo sexual.
Питьё крови — в некотором роде
выражение влечения.