Seems like the story revolving around Tomoya taking his "harem" to a hot spring (https://e-hentai.org/g/1873239/4d8fe2f7df/) is actually a multi-work series. Simply put, I went after the six other stories in the series, which so far as I know, have not been translated by anyone to date.
Put simply, today is Michiru's turn to (a-hem) "ride the Tomoya" ... the Lucky Bastard.
This one was translated by biribiri (https://biribiri.cc), under commission by myself.