Miki lives with her daughter and son-in-law. Their relationship is good, but the only thing that makes her frustrated is that they don't have sex often. While she is spending her days in frustration, she accidentally sees her daughter-in-law Shinichi's huge cock... Kokoro by the manly and impressive thing, she can't suppress her rising urge and milks him wherever she goes. Shinichi, who is sexless with his wife, can't help but devour his voluptuous body due to his mother-in-law's lewd temptations that continue around the clock...