When I was given wasabi KitKats, I remember having a discussion about chocolate with one of my students in which I mentioned that putting chili in chocolate was fairly common in America. She was shocked, and grossed out, at the idea of this combination. Of course, she thought that including wasabi was also pretty weird, but accepted it as something reasonable as a regional variation for novelty value. This is one of those rare cases when a combination is actually a bit stranger in Japan than in the West. I've been reading about American releases of chili paired with chocolate on other blogs for years.
If you look at the top of this box, you can see that there is an old-timey picture in sepia (because that's how we can tell it's "old-timey"). This is because this flavor is supposed to represent what was popular in the Shinshu area during the Edo period. The origin of the hot pepper that is used is thought to be the Amazon basin rather than Japan. It's a transplanted flavor that is commonly called "togarashi" in Japan. Apparently, we have Columbus to thank for spreading it all over the globe, first to Europe and then to Asia. I doubt that makes up for all of the stuff the Spanish did to indigenous peoples nor does it make up for the fact that he is seen as discovering something which was hard to miss and probably was located by many explorers before him, but, hey, credit where it is due. He spread some hot peppers for us all to enjoy, especially the folks in Nagano (formerly the Shinshu area).
I picked this box of 5 mini KitKats up at the airport on my way out of Japan. I don't remember what I paid, but the retail price according to Nestle Japan's web site is 350 yen ($4.38). As is so often the case with these types of KitKat, it represents significantly bad value for the quantity, but one does not buy these for the volume, but rather the novelty. Each KitKat is two mini fingers (about the size of one and a third regular KitKat fingers) and has 67 calories.
When I opened the packet on these, I smelled a very pleasant bittersweet chocolate smell. I deeply inhaled the scent of the bar to try and detect any spiciness or hint of the chili pepper, but there was really no hint. My first bite yielded a mild, slightly sweet bittersweet chocolate flavor with the usual crispy wafer freshness of a KitKat. Only after this did I get a bit of heat on the tongue. Each subsequent bite was the same. It was a one-two punch with each flavor hitting quite distinctly.
This is a pretty nice tasting KitKat, largely because it is a slightly dark, bittersweet flavor which is not too sweet and pairs well with the wafer's crunch. However, the spicy portion seems almost superfluous. It does not detract from the chocolate, but it seems to add nothing. It's like eating a candy bar and then a little hot pepper alternatively.
I think this works best as what it is, a novelty. If you're in the area (or at the airport) and want to take something back for your friends to try which won't make them gag, but will surprise them, this ought to fit nicely. The heat isn't so intense that someone will have a burning mouth. You'd have to be extremely sensitive to hot pepper to suffer for sampling this. Though I'll finish this box (slowly), I don't think there would really be any reason to buy this again.