Koji, a volunteer for Tokyo Free Guide (which is exactly what its name declares; see tokyofreeguide.com), knew only that I wanted to experience something in the city related to food. Instead of taking me to the touristy Tsukiji fish market, he led me to a shopping mall in the Ginza neighborhood. We descended into the basement of the Kotsu Kaikan building, where we found about a dozen gourmet food shops, each one representing a different region in Japan. We strolled through them, munching on free samples and effectively eating our way through the country. We tasted crispy, dried seaweed from the northern island of Hokkaido; buckwheat dough dumplings from Nagano, located in central Japan; and jam made of amaou (a kind of strawberry) from Fukuoka, in the south. Koji explained that these stores are called antenna shops, and they have an interesting function. In Japanese culture, when you go out of town, it’s customary to return with small treats for colleagues. Rather than haul back food from afar, workers will just stop by the antenna shops in the morning before heading to the office—a smart (and sneaky) solution.

2-10-1 Yurakucho Chiyoda-ku, www.kotsukaikan.co.jp