No matter what they do to you, you must never make a sound! If you don't make a sound for 10 minutes during lewd pranks such as soft tickling and electric massagers, you will receive a prize of 1 million yen! However, the Amateur girls who fail one after another challenge themselves to "sex without making a sound" in order to win the 1 million yen! No matter how much they try to hold back, as soon as a dick is inserted, they fail! They forget about the game and feel so good!