Only in Tokyo but looking for something different?
You can often find pop-up shops set up in JR stations selling foods from other regions. I’ve seen them often in Shinagawa near the Takanawa side and Ikebukero near the Central Gate by Tobu. In the last two weeks, they’ve had Tohoku and Kyoto products at the Ikebukero location.
There are also a number of “antenna shops” in Tokyo that specialize in products from particular regions. A number of them can be found in Yurakucho.
by IzzyCaffeinated