While in SF for July 4th, we went to a Chinese restaurant next to a cute store called Genki. Aside from having crepes, it had an astonishingly decent stock of Japanese Candy. Possibly even more than the usual assortment at the local Nijiya.
Another recent(ish) find is the Ichiban Kan in Japantown above the parking structure on the second floor. I call it the Japanese Dollar Mart and you will find Japanese goods there for about a dollar. They do carry items which are much more than a dollar, of course (not being a true dollar store) but it does remind me of the 100 Yen stores in Japan. Predictably, Ichiban sells lots of plastic cases, baskets, tupperware-ish containers, and etc for my undying love and devotion.