Shizuko Ouchi, 61 years old. She lives with her husband and son. One day, while doing the dishes, her son's hand brushed against her back and slid down to her buttocks. He whispered, "I love your big, round ass..." as he caressed it. Though aware it was wrong, overwhelmed by uncontrollable desire, she gave in to her son's advances. What she thought would be a single encounter has now become a daily occurrence, as her son continues to crave her body. Strangely, his love and desire for her grow deeper each time.