In the United States, Kit Kat bars are more or less Kit Kat bars. In Japan, they are chocolaty slabs of innovation. Among the dozen or so kinds of Japanese Kit Kats I've tried, I think my favorite were flavored with soy sauce, which gave the wafers an interesting jolt of umami.
But the oddest new flavors may be those that appear in special-edition bottles of Japanese Pepsi, which over the last few years have included Pepsi flavored with chestnuts, cucumber, adzuki beans, and the fragrant extract from African baobob pods, although I suspect the latter may be less exotic than the tropical extracts that already show up in Pepsi. The shiso Pepsi I tried a couple of years ago was . . . different; a beverage that smelled a little like the herb familiar from sushi bars, but looked and tasted like off-brand mouthwash. I kind of wasn't feeling it.
My friend Carl Stone, a noted composer/gourmand who has been known to quaff wine glasses filled with turtle blood between engagements at Tokyo concert halls, was kind enough to bring back from Japan a bottle of this summer's model: Pepsi Salty Watermelon, a pale, crimson fluid branded with a handsome if steroidal watermelon.