Kaoru, who lives with her daughter and son-in-law, accidentally finds out that they are not having sex. Kaoru sees her lonely son-in-law and herself as someone who is not embraced by her husband, but in fact, her son-in-law is very aroused by Kaoru's big breasts shaking in front of him! Kaoru's frustrated body cannot resist the son-in-law's intense courtship, and they end up having an immoral relationship under the same roof...