Immorality, or also called In no Houteishiki, is a two episode hentai OVA that was released in 2004. Each episode is 28 minutes long. Despite being published in 2004, the art looks 90s. Turns out this is based on the manga Yoru no Houteishiki. It was only one volume that was eight chapters long and was released in 2000. So the art makes sense now.
Saeki Sayoko is a new nurse at an all boys school. She is what you call a diva: nice pretty face, slender body with the perfect curves and last but not least, very well-formed bust. But there is more to her than meets the eye. When boys begin to be found dead overdosed on a potent drug, the trail of drugs and suspicion falls on the very beautiful and very buxom Saeki, the school principle. But more than just drug-dealing is going on after-hours at the academy, including some serious sex scenes. All kinds of sex scenes. Beautiful and seductive Sayako Saeki quickly learns going near the voluptuous principal is dangerous. But Sayako is also dangerous, and the boys sent to investigate her are in for the erotic thrill of their lives–if they survive! All kinds of sex ensues.
I was able to find the DVD of Immorality. So you can go ahead and add that to your collection. I think I know where 22 Jumpstreet got their premise from. If I find that manga, I’ll link it here.