Do i need a visa to purchase and use the JR pass?

Im going on a trip to japan with a few buddies next month and we were planning on buying our passes tomorrow, question is, do I need the temporary visa? I know you can travel in japan without a visa for the first 90 days so we had no original plan on applying for a visa, if anyone has the answers to this it would be a great help. I'm located in the U.S. if that makes any difference.