Rina Uruka, a slender woman with beautiful legs, is known for her sensitive, quick-to-orgasm body that delivers back-to-back climaxes. In this installment of the Challenge! Timer Vibrator series by Taiyo Tosho under the Lighthouse label, a penis-shaped attachment is fitted onto a vibrator and inserted and secured for intense pleasure. With her hands restrained, she experiences relentless, randomly timed vibrations without pause. The release includes a special bonus video of post-challenge vibrator masturbation, making for a highly satisfying experience.