Trapped in the 'wall-pussy' position where her hips are lodged, can she differentiate the 'correct vibrator'? The challenger is Rio-chan, a famous school athlete beauty. Despite feigning innocence with "What's a vibrator...?" her oiled-up, irresistible ass is begging to be penetrated! The first one goes in with a satisfying 'slurp'! Her excited expression, captured on the dedicated monitor, can't be hidden! She even takes the second and third ones! "Is this different...? I don't know anymore!" When she concentrates on feeling the shape differences with all her might, the pulsating vibrations hit her G-spot relentlessly, driving her to a hellish climax! So overwhelmed with pleasure, she can't even think about the answers, her squirting is unstoppable! Of course, the penalty for failing the challenge is a massive load of semen injection!