The adult sweetness line is offered in white, semisweet, and green tea flavors. They're all good, but, surprisingly, I like the green tea one best. I say that because I'm not a huge green tea fan. However, the texture and mixture of bitter and sweet flavors make it a pretty extraordinary mixture of the elements.
Nestle Japan is pretty savvy in how they're shifting the product line and marketing. The birth rate in Japan was 1.3 for 2012. That means the number of kids out there looking to try new candy is going down while the number of adults is much higher. They're going where the money is, and catering to conservative tastes (less sweet, more common and known flavors).
They've done their marketing and 70% of women between the ages of 20-30 are pleased with the matcha adult sweetness KitKat. Their PR talks about how the changes in Japanese society are creating a situation in which women are expected to work late just as men are and they want to position their candy as a way of relieving stress. To that end, they've made a few commercials showing a very thin Japanese business woman being given candy to help her get through the trials and tribulations of her day.
Blogger won't let me embed a video from YouTube Japan, but I'll link to each one here. The one for a green tea KitKat shows the hapless heroine apologizing in English as foreign guests exit. Everything is just fine though after her coworker hands her a box with a green tea KitKat and she munches on it. The second one, for the bittersweet version, shows her exiting a meaning after apparently having done some sort of poor job and being consoled by the same coworker with candy again. Yes, professional failure can always be fixed with candy.
Though this is a pretty stupid set of commercials, which makes it little different from most commercials, the focus is a good one. Many Japanese women have sweets while they're working at the office. They don't eat copious amounts of them, but every female coworker I ever had in Japan kept snacks in her desk. Nestle figures that it might as well be a KitKat.
Beyond catering to the needs of hapless female business people, they're encouraging housewives to enjoy a "gran wafer" with their coffee while their tots nap. The gran wafer (which appears to have lost a "d" somewhere along the way) is a KitKat with chocolate wafers with chocolate between them and no chocolate coating. It is, essentially, a sugar wafer. They're sold 9 to a box as minis, so, you can "have a break", but not a very big one. I guess moms with sewing machines need to sugar-up a bit less than office workers.