I'm working as a salarywoman in Tokyo, and I returned home for the holidays after a long time. My parents and grandfather live in my childhood home; my grandmother has already passed away, and my mother has been taking care of my depressed grandfather. My father has no interest in family life and is always out and about. One day, I heard eerie sounds coming from my grandfather's room. It sounded like the roar of an excited wild beast. Curious and unable to ignore it, I quietly slid open the shoji door. Inside, I saw my mother moaning as my grandfather greedily sucked on her breasts. He was also fondling his cock affectionately, creating a vulgar, shocking scene...