Have you come across a traditional sake shop on one of your walks around town? There are the modern liquor shops that carry all types of alcoholic beverages and there are the traditional sake shops that only carry many brands of sake plus possibly wine and beer.
In the years past, in Japan a traditional sake store not only delivered alcoholic beverages but also had a stand up counter where you could have a drink or two before heading home. Well, you still might encounter such a shop if you are lucky. Found one recently in Yokohama, Motomachi. Old style shop with great selection of sake and a dark wooden counter serving your glass of sake you desire.
Great fun, try if you have a chance.