In Japan, there are 3 thing can be concluded the cheapest in the world.
Electronically things, Cameras and Automobiles. Most of the traveler bought a large numbers of electronically thing to their friends and family, but please remember, the guarantee period is only for 1 year and some of the electrical voltage is for Japan use only. 120V in Tokyo and 110 in Osaka Area. Must check before you buy.
EVERYTHING in modern Japanese apartments is high tech. You use a keycard to get in, but the real innovation is the bathroom. I had to turn the faucet on by hand but everything else seems to work remotely. As you approach the toilet, the lid automatically raises. It flushes itself when you're done, and if you're of a mood to use it as a bidet...well, you have the option of whether you'd like to be sprayed front or back, or both, and the spray is calculated because the toilet takes a picture of your backside to tailor the delivery accurately. I kid you not. Unfortunately I didn't quite understand the full ramifications of the various option buttons and the first time I ventured into the loo, I hit one which speed-dialed the local police department. An alarm sounded, and a few minutes later, some of Tokyo's finest showed up at the apartment door to be sure that no one inside had fallen and couldn't get up. Talk about mortified...
These monsters are all over Japan and sooner or later you're bound to try and use of of them. The danger involved is 'Which one do I use?'
I've seen them come in all shapes and sized selling almost anything that can be put in a machine. From rice till flowers, oh not forgetting the 2 litre beer cans too.(my personal favourite type).
Don't forget the ones in the toilets....
In Japan, the electricity is 100v but it can vary. In international hotels you can find plugs of 110 and 220v. Take an universal adaptor to avoid a tragedy like it happened with my cell phone, it burned!
Take a good guide book, plus a street map and subway map written in your own language. You should buy these before you leave your own country. If you can't read Japanese, and aren't with someone who can, you could be in real trouble without these things, because a lot of signs are in Japanese only, and not many people speak English well enough to give more than basic help. If you don't speak English or Japanese, forget it, you're in deep trouble. Even with this stuff to help you, you're going to get very confused by a lot of things until you figure out how things work.
Japan products are divided in two groups: for local and international market.
Because all the regulations about electronics (PC's, FM's radios, software, cel phones etc), don't follow international standards, is very common that you will buy cheap products that you cannot use in your country.
So, you must buy products for "international use", and you will have no problems