What happens when a timer-programmed vibrator is fixed to a girl's underwear and sends continuous vibrations with intervals of one to two minutes, gradually increasing the duration? At first, the stimulation doesn't feel too intense, but as the vibration time extends, her body slowly becomes unable to endure it. As five, six, ten minutes pass, the girl is pushed to her limits, and the scene unfolds showing her suffering with the vibrator still inserted even after one hour. Watch closely to see what becomes of Yui, a G-cup beauty, in this Challenge! Timer Vibrator release from Taiyo Tosho's Lighthouse label.