Ryuudouji Shimon no Inbou Bonus Episode

A school secretly trains its students to be sex slaves who are then sold to the highest bidder. Ryuu, a male teacher, is entrusted with training the students. The head mistress, Sayaka, promises him a reward at the end if he does a good job. Spoiler alert:

My husband, Keiichiro, was struck down by illness. Mr. Noyama, our family doctor, said he would need to have a rest for a while. But he hasn’t got well though a few weeks have passed. I have now a concern about myself. Yes, it’s about sex…