Recently, I spoke to my son Charles, who is the head Sensei of our Hikari Dojo (I now assist him). I essentially told him this:
"Son, one of the most important things to remember is that the Naihanchi kata should be the first kata taught. Teach all three before moving on the Fukyugata kata.I firmly believe this to be true in our dojo. Naihanchi is more than a simple drill. If you can do Naihanchi well, you can learn to do all kata well.
If a student learns Naihanchi well, his basics will the good. Then all his kata will look like Naihanchi. But if a student learns the Fukyugata kata and Pinan kata first, he will probably have weak basics and his Naihanchi will look like those kata.
All kata should look like Naihanchi. In fact, Karate can be taught with the Naihanchi kata alone."
In our dojo, Naihanchi Shodan is usually the first and last kata we do.
Charles C. Goodin