Maki was spending the same peaceful life as usual in a family of three, her husband and son. However, one day, when his son witnessed the couple's night life, the mother-child relationship changed completely. A son who asks his mother for sexual treatment every time he says, "I can't stop my erection because I saw my mother's erotic appearance!" Maki who responds even though she understands that she shouldn't do it. And finally the two cross a line that should not be crossed. "What's this ... Son Ji ● Po feeling good ..."