Saki Sunohara is 57 years old and has been married for 30 years. She is a mother of four, with children ranging from 28 to 19 years old. While her large family life is lively and fun, the constant presence of someone at home makes it impossible for her and her husband to enjoy their intimate time. Their sexual encounters have been reduced to quick standing doggy sessions in the bath. Saki thought she just had to endure this suffocating sex life until her sons became independent, but when her eldest son decided to move back home after finding a local job, she finally reached her breaking point. With years of accumulated frustration and an overflowing sexual appetite, this mother dives into the world of infidelity and pleasure for the first time.