Father-in-law had always felt deep gratitude toward his son's wife, "Non-san." She was kind, beautiful, hardworking, and took excellent care of the household. But he eventually discovered her secret—every night, while doing chores, she quietly indulged in masturbation all by herself. From that moment on, his heart was shaken, and his lust for her grew stronger each day. Pitying his daughter-in-law and realizing her nights were still unfulfilled, the father-in-law finally reached his breaking point…