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.
I was just thinking about other 
stuff besides how happy I am.
كنتُ أفكّر فقط في أمور أخرى 
.عدا كم أنا سعيد فحسب
Eigentlich sollte ich mich freuen,
aber hatte gerade andere Dinge im Kopf.
Pensaba en otras cosas
además de lo feliz que me siento.
Pensaba en otras cosas
además de lo feliz que me siento.
Du coup, j’ai pas mal
de pensées qui m’assaillent.
Invece di godermi il momento,
mi sono perso in altri pensieri.
Só me ocorreu o quão feliz fiquei.
Я так задумался, что даже
обрадоваться не успел.