There's also the
Naked School series(?) from
You must be registered to see the links
.
As for negatives (at least, compared to your requested requirements), these games generally imply that the male characters are naked, but rarely ever show it (except for sex scenes). Also, it isn't a case of all people are expected to be naked – just the students of the academy.
Since the setting does not include change-in-common-sense or mind control of any sort (just a school mandate), they put a lot of emphasis on the girls' embarrassment. Maybe this is a good thing, maybe you're looking for something more candid.
Lastly (and probably most importantly), most of these games have not been translated to English, nor do they seem to have any plans for it. There are a couple of MTLs around F95, though...