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.
So fantasizing about sucking girls' 
blood could pass for a joke,
لذلك فتخيُّل مصّ دماء الفتيات 
،يمكن اعتباره مزحة
Das gleichgeschlechtliche Saugen
könnte als Spiel durchgehen,
y fantasear con las chicas
puede pasar como broma,
y fantasear con las chicas
puede pasar como broma,
donc tu peux t’imaginer le faire
à une fille pour rire,
quindi immaginare di farlo a una ragazza
può passare per uno scherzo,
Fantasiar chupar o de garotas
 pode parecer piada,
Значит, от фантазий с девушками
можно отшутиться,