Man this one has been something I've been trying to get off the ground over the years....
Essentially, monster girls are real, and of course they need an education in how to not only use their charms and bodies, but also general mathematics and other learning things. So over 100 years ago, Madam Arachne, a Spider-Woman, formed the school within her castle in eastern London, hidden by magic making it unreachable by normal humans...for the most part.
Madam Arachne's is a safe haven for monster girls to learn and grow, starting at age 16 and moving up through college as well. Girls are expected to live on campus, attend classes, and may make trips to the nearby monster settlement for fun and a bit of adventure, though the woods behind the castle are strictly forbidden, as not only are there male monsters there that are savage, hunters also roam the woods in search for these monsters, not caring if you are a savage beast or a well meaning monster girl.
Now,the way that I had envisioned this is that human males ARE allowed on school grounds, and are even given an education much like the monster girls, but monster girls also feed on the human males "essence" through sexual intercourse with them. After 5 years at school, the males are turned out into the world again, with their minds wiped of everything but their education so that the world remains none the wiser of Madam Arachne's school.
Now, depending on interest, I may be willing to change things and make it a general school for monsters, both male and female, and leave out humans altogether, but....here's the basic idea. ^0^
If you're interested just post or comment. Thanks. ^0^