Kit Kats have become so popular in Japan, that Nestle asked top Japanese patissier, Yasumato Takagi, to create two special flavors of Kit-Kat for adult tastes, under its new Kit Kat Chocolatier line.
The Kit Kat Wine contains 0.12% alcohol by volume, and is based on a powdered version of French red wine inside the cream filling, giving the white chocolate a light purplish tone. It has a distict wine aftertaste.
The other variety is Kit Kat Noir, which has a rich and strong aroma of cocoa mass. Roast cocoa beans are used to produce a bitter flavor and scent. The wafers are filled with an almond and hazelnut cream.
You can actually order these online from J-List (NSFW)