Old Japanese currency

My sister last visited Japan about 11 years ago and she had quite a bit of Japanese currency leftover from that trip. We'll be making a family trip to Japan next week and she intends to use that leftover money for our trip. She has not shown me the money so I am not able to compare to them to the new currency that I have with me.
My question is: Has there been any change in the paper money from 11 years ago and will she still be able to use her leftover money?

No changes - 11yo currency will be just fine.

Hi Paul, thanks for the info.

My sister last visited Japan about 11 years ago
and she had quite a bit of Japanese currency leftover from that trip.

Did your sister go to Okinawa?

She may be holding some 10000-yen, 5000-yen and/or 1000-yen banknotes of the older Series D.
Such Series-D banknotes are still valid, though some young cashiers (such as part-time students) might not know them.

It was on the 1st of November 2004 (about 12 years ago)
when the newest Series-E banknotes of of these three face values began to be issued.

Concerning 2000-yen banknotes, which have been issued since 2000,
Series-D is the only and current series;
but they are seldom used as currency except in Okinawa, where they are much popular.
Banknote checkers at many soft-drink vending machines do not recognize 2000-yen banknotes.

- National Printing Bureau: Basic information on banknotes:
　Old Series-D banknotes
　http://www.npb.go.jp/en/intro/kihon/kako/index.html
　Banknotes currently issued
　http://www.npb.go.jp/en/intro/kihon/genzai.html

Regular Japanese yen coins have been almost the same during these few decades,
with only a minor change of 500-yen coins in 2000.