Sasahara Rin, a fair-skinned beauty with soft E-cup big tits, takes on the Cowgirl Position Time Trial challenge. The rules are simple: if she can make him cum within three minutes using the cowgirl position, she wins a cash prize—if she fails, she faces a punishment. Eager and full of energy, Rin dives into the challenge. After penetration, she skillfully jerks him off, quickly bringing him to full arousal before mounting him in the cowgirl position. Amazingly, she succeeds within the three-minute mark—truly a pro at work. However, due to the tightness of her expert pussy, there wasn't enough "length" in such a short time, so she decides to go for a rematch. The second round ends in failure, leading to her punishment: a rimjob. Bonus scenes also include Rin enjoying a shower masturbation session.