It might be a commonly-known thing, but one type of ice cream you can buy easily in Japan is green tea / matcha ice cream!
You can buy it in America, but it's definitely a lot harder to find. In Japan, Häagen-Dazs even sells their own version in grocery stores. I didn't buy their brand, though. Instead, I got it at a little ice cream / takoyaki / snack bar in a small town I was sight-seeing in. It was good, although a bit overwhelming flavor-wise after a few licks. I'm sure that depends on the maker, though -- I might've just been unfortunate to have my first time eating matcha ice cream be with extra matcha!