I found an interesting anime / manga called "dokyuu-hentai-hxeros". There seems to be a lot of ecchi stuff in there, but of particular interest was Episode 2 of the anime and Chapter 18.5 of the manga. In this, a creature has brainwashed the school into thinking that nudity of the new school uniform, and the two protagonists are forced to spend the day naked as they try to locate the monster.
Anime link:
https://hentaibar.com/videos/2572/do...nglish-subbed/
Manga link:
https://isekaiscan.com/manga/dokyuu-.../chapter-18-5/
I'm not certain how safe the links are, so feel free to use your own anime / manga site.