Finally, Karen Amatsuki makes her debut in the "Back" series! Her thighs tremble as she deepthroats a vibrating dildo! She finally gets to film a secret shoot with Director Mizuchi, whom she adores like a father, and he takes full advantage by pushing her limits with his massive cock! As she gags on him, Karen reveals everything about herself - including her tight throat that can take it all! On the brink of passing out, she gives us an unforgettable performance!