Kaya Miyoshi has a petite, voluptuous figure, trained through karate and boxing in junior high. Though she's calm and caring toward her friends, she's prone to some rough behavior. One day, she's summoned to an empty classroom by her uncle, a school employee. He presents her with forged report cards and recommendation letters and threatens to prevent her from continuing to college if he reveals them.
Kaya resists, but even her robust stamina is powerless against the employee's clever blackmail. The middle-aged man's oily hands roam her voluptuous body. At first, she's filled with disgust and resistance, but his persistent, tenacious caresses gradually make her body respond. T he man's penis penetrates her petite frame, reaching deep into her uterus. From that day on, Kaya's life changed forever.
A few years later, Kaya marries Akito Takagi and appears to be building a happy family. However, her relationship with that man is not over. While her husband was busy at work, Kaya continued to meet the man secretly. It was no longer a threat, but something she herself desired. After marriage, Kaya continued to satisfy the man's desires with her voluptuous body. Her mind was completely dominated by the man.