Enjoy. It's great fun. You pretty much can't miss by just walking the streets and allies. There are formal shops that sell fancy packaged products and then a host of small shops and vendors that specialize in every subcomponent for virtually any gadget you can think of.

My favorite spot in Tokyo? I found a neighborhood of shops that sell the plastic display sushi found in Japanese restaurants world-wide. There were many different grades of plastic sushi, from poorly colored artificial in appearance, to nearly indistinguishable from the real thing. At one of the shops specialing in the very best plastic sushi, my traveling partner purchased a frosty cold mug of Asahi, with beads of moisture on the outside of the glass, a few droplets of trickling down the side, with a perfect just-poured head as well, all in plastic.

I love Japan. Prepare to be amazed.