It has been three years since Nanami started providing sexual relief for her son. It all started when she felt a sense of crisis when her son continued to shut himself in his room and masturbate, so she helped him. Of course, she knew it was wrong, but she convinced herself that it was a temporary measure until her son could return to society. Although her husband does not get to the heart of the matter, he seems to be suspicious of their relationship. She tells herself that she needs to end this relationship as soon as possible, but her son does not listen to Nanami's persuasion and only wants her body. And so their lewd relationship continues to drag on...