Kono Watakushi ga... Konna Shokushu de Iku Nante! ~Shokushu Bishonure Kouman JK Anju~

Tokumei is a male teacher in a certain girl's school. His true identity, however, is a space alien who breeds and sells tentacles for various sexual uses. Mei, one of his students, is being used daily as test subject for new species of tentacles. One day, Anju accidentally witnessed their abnormal experement... And so, they turn her into the new test subject.