A Natural Airhead isn't an airhead at all. They are people who aren't aware of bad things, bad intentions, or bad people around them. These people are usually portrayed as kind, pleasant,nice, clumsy, shy, and easily embarrassed, and will always try to do the right thing and will always see the good in people.
In Asian shows such as dramas, animes, and movies, is where the characteristics of an Natural Airheads are usually seen.These characters are usually girls who are cute and shy. =)