[F Taku (Anma)] Iyada to Ienai Jimikei Shoujo to Inaka no Ojisan 4 | The Girl Who Can't Say No and the Uncle from the Countryside 4 [English] [Rei Scans] [Digital]
It looks like the author is trying to expand their works by doing something else other than gangbang. I also feel like this series works better being its own universe rather than being a prequel.