Advice: Shops for Stones in Tokyo & Kyoto

I'm off to a trip to Japan in the Fall, and I would like to add to my natural stones. Does anyone know of shops for stones in Tokyo or Kyoto. Years ago I acquired stones at a shop called Nomura in Asakusa, Tokyo, but I cannot tell if they are in business any longer from a web search. I would appreciate knowing of knife shops that have a good selection, but especially of any shops (like Nomura) that specialize in stones. Thanks!

Frege I am also going to Tokyo in September and am also interested in the same thing. I'll have to keep a eye on this post to see if anyone knows of some good spots

Morihei also close to Asakusa