My nephew Toshiki started cleaning the room in a hurry when he suddenly decided to stay in his apartment with his aunt Sayuri, who came to Tokyo from the countryside. Before the cleaning was finished, the doorbell rang and Sayuri came over. Toshiki is surprised to see Sayuri's youthful appearance after meeting her for the first time in a while. "For the next three days, I'll be alone with such a beautiful aunt in a small apartment room..." While thinking about such things, Toshiki's lower body goes out of control against reason...
