I spent 3 years in Japan, and there's no downtown place besides Sanko that carries certain Japanese specialties I happen to love. Besides all the usual supsects (sushi-making supplies, ceramics, comics, noodles, edamame, miso etc.), they have wonderful harder-to-find goods like tsukemono (all the yummy pickled things), umeboshi (pickled plums), Japanese-style onigiri (formed rice balls with various middles), and the best soft drinks. I also love the automated greeting recordings.