There is an anime that I remember reading the description of and I've been trying to find out which anime it was.
A summary of the anime:
A high school student is fascinated by a particular school (that may have been very prestigious). The students at that school try to warn him against joining it. When the MC joins, he is horrified to find out that everyone at the school (except maybe all/some students) is a robot and there is strict surveillance on all students; and the MC, now having joined can not leave. He decides to (maybe with some other students) attempt to "break out".