These Kinako Kit Kats are the last of the trio that I got from my dad earlier this year, and has quickly become one of my favorite Kit Kat flavors. Granted, I like Kinako (soybean flour) to begin with, but I think that even someone not familiar with it would like this also.
Kinako is sort of difficult to describe, but I think a "peanut butter-ish" smell/taste is the closest I can think of. Kinako by itself is not sweet, but usually for desserts and sweets it is mixed with sugar before being used. The nuttiness of the Kinako lends itself really well to the chocolate base, and on the whole it's not sweet but still satisfying for a little snack. Not surprisingly, this Kit Kat goes really well with hot green tea, haha.
Kinako is still a relatively unknown item outside of Japan/Japanese markets, but hopefully one day it'll become more widespread and as common as green tea - these Kit Kats are great!