Even when they can not be seen in plain sight, invisible girls still fall victim to embarrassment. Situations like these involve the female character(s) becoming invisible, but however their clothes aren't. So in order to become fully invisible, they must strip off every piece of clothing they are wearing. For example, here are pages from an ecchi doujin called "Transparent Girl." This one involves a girl who was tricked into drinking an invisibility potion.
Feel free to post anything that involves invisible enf!!!