[Locked] Trying to find the name of a loli Doujin

A long time ago I read a loli doujin about a man who moved to the night shift and had to find a new bath house. This particular bath house had a young girl (I think her name was Karen-chan) operating as an "assistant" in order to keep some of the long time customers returning to the failing business. Shenanigans ensue.

Does anyone know the publication this came from or the name of the doujin?