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.
and there's even a welfare 
system for demi-humans
كما أنّ هنالك نظام خدمة اجتماعيّة لأنصاف البشر
Um den Benachteiligungen der Halbdämonen
im Alltag entgegenzuwirken,
y hay un sistema de protección
para semihumanos
y hay un sistema de protección
para semihumanos
et un système de soutien
a été mis en place
ed è stato persino istituito
un dipartimento previdenziale
Criou-se até um sistema
 de bem-estar àqueles
и даже появились программы
поддержки полулюдей,