18+ Bi-Indoushi Miija: Injoku no Gakuen

A pentagram appears in the school grounds of St. Moses Academy, and the demon of lust Mija is unleashed into the world to resurrect the dark paradise on earth once more. Her role is to covert humans to her debauchery... to reveal the hidden lusts and carnal pleasures to her human converts.

Sara Tadeshina starts her investigation. Given only cryptic clues to guide her investigation, Sara tried to get to the bottom of her mysterious mission. Meanwhile, a young student, Mayu, is dragged into Mija realm. Under Mija spell, Mayu learns about the pleasures of the flesh. Kotaro, secretly nursing feelings for Mayu, sees a disturbing change in her behaviour. He follows Mayu and bravely enters Mija den to try to save his love. Will Sara be in time to save both Mayu and Kotaro? Will she be able to defeat Mija and her converts? Follow the sexy adventures of Sara, Mayu and Kotaro to find out!

(Source: AniDB)