[tommasi]

From my personal experience, buy a new laptop if your current one is rather old.

Japan offers some of the best consumer electronic goods but they are not cheap.

To tell you the truth, it is much cheaper in the US and you should take advantage of it before leaving.

Medicine is also another things that you should make sure to bring some.

There are local brands but at first you may have difficulty choosing one and if your Japanese is not strong, you would have rough time finding it.

If you are still in the early stage of learning Japanese, maybe you should buy some textbooks in the US so explanations are in English rather than in Japanese.

Graphic calculator might be useful as it is harder and expensive to buy one in Japan.

Other than that, make sure to buy your favorite liquor at the duty free shop cos in Japan, you don't see too many foreign liquors at the regular stores.