The fourth and final installment of the popular series MILK Junkie! In order to monopolize the main character Wataru, even during a three-girl contest to compete for the world's biggest breasts in the Big Breasts Grand Prix, she sneaks out and has exciting sex with Wataru. This time too, big breasts, huge breasts, and a mess! ! Who will win the Big Breasts Grand Prix? And who will get Wataru...?