Kurea Hasumi has overcome rigorous training to become a special investigator. Having consistently ranked at the top throughout her training, she now faces a final test: "Pleasure Endurance Training." This grueling trial requires her to withstand intense stimulation to sensitive vaginal areas using a powerful vibrator, all while suppressing orgasm. Additionally, in the "Sex Training" phase, she must endure an extremely thick penis thrusting deep into her uterus and repeated consecutive orgasms induced by a piston machine. However, this training is not merely a test—it's part of a sinister organization's conspiracy. Kurea's body becomes an experimental subject designed to heighten sensation, relentlessly penetrated by increasingly bizarre men. Unable to withstand the relentless waves of pleasure and repeated creampie after creampie, she gradually loses control of her own body...