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.
Liar! You were thinking it's nice to be young,
،كاذب! كنتَ تفكّر أنّه من الرّائع أن أكون يافعة
Lügner! Dir steht ins Gesicht geschrieben,
dass dich Jugendliebe geil macht!
Mentira. Pensabas que es bueno ser joven
Mentira. Pensabas que es bueno ser joven
Menteur ! Vous vous dites :
« Ah, c’est beau la jeunesse ! »
Bugiardo! Pensavi che è bello essere giovani
o che mi sto godendo la gioventù!
Mentira! Pensou em 
como a juventude é boa,
Врёте! Небось думаете, как старикан,