There have been over 300 regional and seasonal KitKat candy flavors in Japan since 2000. A new regional flavor has just been announced, celebrating a specialty from Ogasawara Town located in Tokyo's Ogasawara island chain. The Ogasawara island chain is a UNESCO World Heritage site, and difficult to get to. The only way to get there is a 24 hour trip by ship from mainland Japan.
The new KitKat flavor is made with "island lemons" an Ogasawara specialty. The fruit is about one and a half times the size of a regular lemon and has a more rounded shape. Local people in Ogawawara add the juice to shochu (a clear alcohol made in Japan) and call it mizu lemon (lemon water).
Would you like to try this flavor? Do you have a favorite KitKat flavor? I don't think I have tried a flavor I didn't like. You can check out some of the other flavors on this Wikepedia page.