LF Doujin Guy takes job as a dormroom keeper for multiple girls

My memory could be wrong but: The doujin set in a dormroom. The guy takes over his grandfather's or uncle's job as the dormroom keeper for multiple girls (who might have been sisters). I remember at some point he cooks for them. He ends up having sex with some of them one by one, not sure if at any point with multiple at the same time. He gets caught by one of the girls while having sex with another one. Sorry if the description is bad, was a decent time ago.

Have been looking for a long time but cant seem to find it.