These days, Japan is thronged with tourists from overseas. We see more souvenir stores here and there for them. Going in, you often see just "GREEN" area!! Sometimes, green for Wasabi, sometimes, green is for TEA!
I often find an interesting stuff that I don't see the regular supermarkets Japanese usually go to. This is one of them: Matcha Latte Liqueur.
I don't buy anything from those stores, but it is fun to see what they have. They have a lot of things which are "Japanese-'ish'".