Natsuno Kohaku appears to be an ordinary adult student, but she is secretly Agent Kohaku. While infiltrating a hideout with her colleague Yano, she is captured and interrogated—only to discover that Yano was working for the enemy all along. Trained to withstand pain, she is quickly exposed as helpless against sexual stimulation. Her huge breasts and sensitive nipples are tormented as she is spread-eagled on a bed, chained upright in a cell, and forcibly creampied. Despite the humiliation, an unmistakably blissful look begins to spread across her face.