More than a decade after divorcing her husband, Natsumi still shows no interest in remarrying, and her son Sho worries about her. By Sho’s final year of high school, a man named Kitano begins visiting their home and Natsumi’s behavior gradually changes. Concerned, Sho peeks into the room where the two adults are together and witnesses a shocking sight: Natsumi moaning as she takes Kitano’s cock in her tight ass. He cannot forget the anguish on his mother’s face...