Toromitsu Musume no Hitou Service: Torottoro Churu Churu Gohoushi Sasete Kudasai

トロみつ娘の秘湯サービス ～とろッとろちゅるちゅるご奉仕させてください～

Based on the CG collection by Churu Bitch Churu Churu (ちゅるびっちちゅるちゅる). On a sunny holiday he took a drive to a certain rural village and awaiting him in an open-air bath were, unexpectedly, three little loli girls all in naughty outfits. The three introduce themselves, and the service begins... (Source: DLsite English, edited)