Last name is first on a JR Pass voucher

Recently I purchased a JR Pass, and the voucher came in the mail. I am an American with a first, middle, and last name. Suppose my name is Samuel Nathan Clemens, which shows up on my passport as:

SAMUEL NATHAN CLEMENS

On the JR Pass voucher that came in the mail, it says:

Mr CLEMENS SAMUEL NATHAN

Is this a problem?

Edit

Relating to phoog's comments, I eventually took another look at my passport, and lo and behold, the last name was first on the passport as well. But one thing that was interesting was that they somewhat avoided the whole discussion by just putting the last name in one field and the first and middle name in another.