I went there! It's the real deal - felt like I had stepped through a doorway into a shop in Japan.

I bought a bag of genmaicha (toasted rice tea), which I've always liked, even though I know it's what the peasants drank. The store is quite expensive (a matcha making starter kit, with bowl and whisk is $90) but the bag of tea was $14 or so.

Thanks for the recommendation.