I visited and stayed in the Odaiba area which didn't have a lot of shops. There were many in the Tokyo & Shibuya area. Google Maps will get you a good list with directions and travel options regardless of where you happen to be.
Our lack of Japanese language did present transportation challenges. Taxis are easy, and the most expensive option - trains are everywhere and ticket systems were all in Japanese. They did have buttons for language changes but 90% still remained in Japanese vs English when we gave it a shot.
I think you'll have no problem finding shops - The ones we did find were organized well and had high quality inventory. Shops I did visit usually opened around 11a so getting an early start wasn't an option. We had similar experiences in Tokyo, Kobe, Fukaoka, Hiroshima, & Nagasaki.