Wife Riona lived a fulfilling life working alongside her husband. One day, when her husband went on a business trip, she was left alone to care for her father-in-law. However, dealing with her lecherous, senile father-in-law pushed her to the edge, and in a moment of frustration, she struck him. He had no ill intent—his actions were merely mischievous—but Riona was overwhelmed with guilt and remorse. The next day, while she was tending to him, her father-in-law became aroused and forcibly took her. Though she resisted fiercely, his earnest, skillful touch brought her to an unexpected climax. Long deprived of pleasure, Riona found her heart shaken, gradually drawn into a forbidden relationship with her aging yet passionately lustful father-in-law.