Rieko has been married for three months to a man with a stepchild. Her relationship with her husband is good, but she still hasn't gotten to know her son Kazuya. She can't stand it, so her husband suggests a family trip for her... Kazuya, who begins to feel the charm of Rieko as a woman, is unable to suppress her rising desire and pushes her down. She climaxes over and over again due to the sloppy piston and her relentless caress.