Sandwiched by my wife and her sister

A couple who had met in their high school years and married later on are having a happy and adventurous sex life. Wife works as a manager of the restaurant which brings in the money while her husband stays at home taking care of household chores everyday. The young wife is adventurous, fun-loving and she never turns down sexual advances launched on her by her husband. These were all peaceful days until one day the wife's sister, a college student, moved in. While their curiosity was growing, there was a secret adventure developing between the husband and his sister-in-law living under the same roof. One amazing voyage awaits them at the end. [Edited from MangaGamer]