Kazuko, a devoted mother who goes too far in caring for her son's education, ends up tending to his physical needs as well. One day, while giving her lifeless son a blowjob to cheer him up, she is accidentally caught in the act by his private tutor. The tutor seizes the moment, taking incriminating photos and using them to blackmail Kazuko, forcing her into a life as his sex slave and cumdump.