Based on the adult manga by Shiwasu no Okina.
Ayano-sensei is a teacher in a lesbian relationship with one of her female students. When helping to clear out the old second school building, she finds a flash drive with pictures of women having sex... women with dicks of their own! Her investigation leads her to one of her very own students, the president of the black magic club. He can make it happen, but it's not gonna be easy.
(Source: H-Moe)