Yuka, a diligent female college student, was not satisfied with sex, but something happened that destroyed her values ​​regarding sex. When she was young, her father's friend Akigawa, who had been her tutor, got drunk and attacked Yuka, whose body had developed into that of an adult. Yuka was confused, but halfway through, her body and Kokoro melted away from the skilled technique of the middle-aged man, something she had never felt with her boyfriend... From that day on, she became extremely sensitive and became aroused just by seeing an older man.