Kit Kat comes in a wide variety of flavours in the orient, matcha (green tea) flavour being a big seller. Can buy them in the Japan Centre in London, but extremely pricey so haven't bought any.
Mrs O came back from a gathering with fellow Japanese yesterday with a matcha Kit Kat, only two fingers half the length of normal ones, so i tried it. The chocolate and inside is all green, the tea flavour is detectable and the taste pleasantly lacking the extreme sweetness of conventional western confectionery.
I love matcha ice cream in summer in Japan, very refreshing, but not so sure about the Kit Kat.