Seikoujo Dark Chapel 聖肛女～背徳の美臀奴隷～

Sister Rosaria, stumbles upon a priest having sex with a recent widow. Imagining herself in a similar position (her husband recently passed, so she became a nun), she begins to masturbate. The priest, the protagonist, discovers the sister’s peeping and proceeds to sexually abuse her into not saying anything about what she saw. Within a few years, our nun has tried to space herself away from such terrible memories and began her new life in a church far away. However the sexually deviant priest has discovered the nun’s whereabouts, murdered the previous priest, and has taken his place at the same church she works. He further begins to extort Rosaria again. He will also be helped along by his new nymphomaniac nun, Liz...