A friend let me some yen bills and their condition is not good

Hi!

A few months ago, my friend let me some yen bills from when he was in Japan. The thing is, their condition is not that good.

So I'm not sure how I should proceed. Should I go to a bank when I arrive there so they give me different ones in a better condition? My main concern is not knowing Japanese, of course I can use a translator, but just to be sure if its my only option, or if their condition is not "that bad"

Picture of my yen bills