Although I have a hard time believing
Naru could mistake the Juggernaut for
anything but a massive wall of flesh, I
really liked the way it turned out.
Author's response
Keep in mind Keitaro was submerged underwater to his neck, and Naru was glasses-less. She dipped her hand underwater to feel his chest up, and the steam prevented her from seeing the size difference between him and Kitsune.