Waltz, a tiny standing bar that specializes in natural wines, is nearly impossible to find the first time you try looking for it. On a recent Saturday evening, the bar's obscure location — on a dimly lit backstreet between Tokyo's Ebisu and Shirokane neighborhoods — confounded me and two of my friends, as well as the GPS function on my cellphone. Waltz's service info lists no phone number, probably because the bar fills up so quickly that owner Yasuhiro Ooyama has little time to field calls from lost customers. By the time we arrived, the watering hole, which can fit around 10 guests, was already packed with regulars sipping glasses of unfiltered vin naturel in various hues and nibbling on homemade charcuterie — and the doors had only been open for 20 minutes. At 6:30 p.m., Ooyama began turning customers away.

My friends and I had gone to Waltz in search of Georgian wines. Earlier that night we'd attempted to visit La Pioche, a bistro in Ningyocho that importer Yasuko Goda of Racines had recommended for its selection of kvevri wines. Much to our dismay, La Pioche was closed when we got there, although I later learned that the bar usually offers a few Georgian vintages that change with the owner's fancy (like several natural wine bars in the city, La Pioche rejects the notion of a regular wine list).

We were about to give up when I remembered that Goda had also suggested checking out Waltz and Rakki, a Chinese restaurant in Gaienmae owned by Shinsaku Katsuyama, who also runs the venerable natural wine bar Shonzui. As we had time for only one glass of wine, we headed to Waltz. Once again, however, luck was not on our side.