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.
Huh? We're done already?
ماذا؟ انتهينا بهذه السّرعة؟
Was?! War’s das schon?!
¿Eh? ¿Eso es todo?
¿Eh? ¿Eso es todo?
Quoi ? On a déjà fini ?
Eh?! Abbiamo già finito?!
Hã?! Já acabou?
А? Уже всё?