I mentioned Vinegar drinks in a prior post. These Kit Kats are flavored like those drinks. The Apple Vinegar one above is white chocolate. The Lemon Vinegar Kit Kat, below, is regular chocolate.
The vinegar drinks are quite good. I just bought an Ume (plum) flavored vinegar drink. I'm a bit addicted now.
These are Zunda Mochi Kit Kats. That's Edamame (soy bean) mochi (sweetened rice paste) flavored Kit Kats from the Touhoku (Northeast) region. They were passed on to me from a friend of a friend of a friend who lives in Misawa.