Ren has a tense relationship with her son from her second marriage. The son falls in love with his beautiful stepmother, who is close to him in age. Feeling he has reached his limit, the son decides to leave home. One last trip to a hot spring for the mother and son... a trip that was supposed to cut off his attachment to his stepmother. However, his feelings for her grow stronger. Unable to bear it any longer... Ren has realized that her son has feelings for her. She tenderly kisses her son, puts her hands on her breasts... and takes her son's penis into her mouth. A drama of forbidden love that will never be fulfilled.