you can buy the tickets of Japan Rail Way below URL.
Have a nice trip!
yes or you can be goggle JR Japan Rail Pass
no no no you can check Japan rail pass website clearly.not advanced 90 days .do it worry about that.you know you are Americans you can stay in Japan without Visa 90 days.do not worry
you should buy tickets JR rail pass Japan.you can check website Japan Rail pass .hope to enjoy staying in Japan while you are here .
i understand but JR Rail Pass is just noe big train company here .do not worry