I read it a long time ago on the

doujin toshokan site, but they are dead now.

I think it's longer then 1 chapter.
I think the story revolvs around a theater club in school, a new member want to join the club. They invite him/her (sorry don't remember) to an abandoned old gym or a big storage room. It's fairly run down, and there the character must have sex and the leader of the club and some members are watching them from above. This was some sort of test, to see that the main can play any role.
Sorry, but i remember only this from the storry.