The place Damon refers to with the cool electronics shops is Akihabara. As a side-note if you present your passport you usually won't have to pay taxes on the goods bought in that district. Some kind of deal they have worked out since it is an often visited place by foreigners.
Right there in the Ginza district where you are staying there is a nice little knife shop with a lot of custom stuff. I can't remember the name of the shop, but it is very near the Kabuki Theater, across the street I believe. Anyone in the area should be able to point you to the theater, as it is a very famous place. I think you will be surprised by the genre of knives you find though. The Japanese taste in custom knives is very different from the US. Tacticals are basically non-existant. (autos are VERY illegal, btw) Knives are very expensive over there, as is anything, but the custom market is small and geared toward dainty and artsy stuff, and hunters/skinners. Damascus is a rare find over there, but natural handle materials and mirror polished blades are prevalent. That is the only knife shop I ever found in Tokyo with custom knives. There are several shops here and there with the standard Benchmade, Spyderco, etc. fare. One I remember in particular is in a district called Asagaya. They have a long thoroughfare there thats sort of an open-air mall. All kinds of shops, and one or two have a pile of knives. Don't remember seeing anything unique, but you never know. Mostly standard prod stuff that we can get here. One of the shops there had an older Japanese gentleman sharpening knives old-world Japan style with semi-submerged water stones. That was a blast to watch. He was givin it both barrels too. Had a pile of knives he was going through, apparently the locals brought a lot of work to him, mostly using knives---kitchen/chefs knives and the sort. It was fun. As to the other aspects of Japan, be open minded and don't let the frustration get to you. It is VERY expensive, and damned near impossible to find your way around without some type of help. If you are staying with a friend who lives there then you should be all set. If you're the average green foreigner tourist, then maybe the hotel where you stay will have some helpful literature. USE it. It is easy to get lost over there, especially on the train system. It is very efficient, but a bit confusing. Most of the station workers speak a little english though and are happy to help. WHEW that should about cover it. In case you were wondering I lived in Tokyo for 7 years (USAF). GREAT city, I really miss it. The people are very polite, if a bit standoff-ish. They just fear embarassment by not being able to communicate very well in english, don't hold it against them. On the other hand, there are a lot of them who jump at the chance to practice their english. It all depends. Have patience and Have fun! jeff