Japanese Sites

Is it possible to buy off of other sites in other countries such as japanese websites? and if so how do you do it?

It is possible providing they're willing to ship internationally.  Google translate + intuition of what things actually mean + paypal + knowing how to convert yen to dollars will all be major factors.  If their website does not offer a shipping address outside of Japan, you could always email them and ask politely.  Use good spelling, and offer a google translate version with your English request.  Don't forget about apologizing for your terrible Japanese due to needing a translator. :D  Good luck.

I have bought from amazon.co.jp and http://www.hmv.co.jp/en/

>>2
how does buying something in Yen with dollars work?

Or do you have to convert your dollars to yen beforehand?

>>4
If you're using a credit card that allows international transactions, they'll convert for you (and most will charge a 3% transaction fee).