It's basically Prison School if you removed the personality and motivation for all of the characters. It was interesting in Prison School seeing the characters resist and fight against the torture to try and escape, however this completely lacks that aspect, the MC gives into it almost immediately and the girls continue to torture him despite his attempts at total and complete submission. It was also clear in Prison School that the author had done research on torture, from it's methods to it's effects to how people deal with and resist it. This lacks such understanding, so it's impossible to sympathize with the MC because none of the characters even remotely resemble real people. I'd say it was just M porn but it isn't even that, it lacks the carrot and stick aspect you see when actual masochist write femdom. It reminds me of someone who clearly isn't an M but is trying to write for that audience because they need a paycheck.