is there anything specific you need before going to japan?
 

because if there is i would like to find out beforehand

The definition of vague:)

Money. A good pair of walking shoes.

Passport would help.

A wallet that carries coins... Coins are used in Japan a bit more than the US. (They have 100 yen and 500 yen coins which are basically a dollar and 5 dollar coins!)

A sense of adventure and an open mind.:) *Notes that I've never actually been*:p

Plane tickets would help too I guess.

Aside from the obvious of a passport, plane tickets, an idea of where you're going to stay and travel money, no.

Freshly laundered underthings. For you never know if you're going to be hit by a bus.

Oh, right. Cloths.