Angel of Darkness 5 (1997)

College life getting you down? Switch to Seika College where the students are getting a whole new lesson in sexual education! Michiru's clas ses were dull and boring until her classmates, Chie, Saori and Takeru, started taking extra classes at a new night school. Utilizing subliminal messaging, the school helps their students ace their daytime college exams. Unfortunately, the school's professor forgot to mention the process has a few sexual side effects...
The next day Saori's in for the sexual education of a lifetime! Classmates begin masturbating, her professor is fondling the other students before her eyes, and Saori is getting so hot she's literally exploding! Then, on the way home, Chie finds her sexual appetite soaring. She'll take any man, or thing, that can relieve her inner burning desires!
Can innocent Michiru uncover the truth behind the evil night school and the mysterious deaths of her friends before anyone else dies? Or is she fated to become another victim?