His mother, Miyuki, is more erotic than anyone else. This was something that her son noticed some time after his father left home for work. Frustrated, Miyuki was so absorbed in masturbating that she didn't notice her son watching her. The sight was just too erotic... The son, knowing it was a forbidden relationship, still yearns for his mother, and the mother, unable to resist. Having crossed the line, the two pursue each other to the extreme.