With her husband and son, Maki leads a peaceful life as usual. However, one day, her mother-child relationship changes completely when her son witnesses her husband and wife's nightlife. A son who asks her mother for sex processing every time, "I can't get an erection because I saw her mother's erotic appearance!" Maki agrees even though she understands that it is wrong. Finally, the two cross a line that should not be crossed. "What is this... my son feels good..."
