Based on the eroge by M no Violet.

Before Ren Nanase was ever a night shift nurse, she was a sexy coed at a nursing school. Hearing rumors that one of the faculty is a rapist, she does exactly what any model citizen would do and confronts him about it. Unfortunately, things go downhill from there, and she winds up being his sex slave, getting a crash course in depravity. But in the middle of that perversion, could there be a hint of purity?