Gishi-san no nureta futomomo

Original title: 義姉さんの濡れた太もも

Nari runs the hot spring inn left behind by her late husband. One day, her husband's younger brother, Koji, returns home. The next morning, upon waking, Nari finds herself transformed into Makiko in a Tokyo apartment; she realizes she had merely been dreaming that she was a widowed innkeeper in the countryside...