Here's a video about the 1962 currency reform that gave us the won currency that South Korea currently uses. I added titles and subtitles in English and Korean. You might have to turn on the subtitles to see them.
Pretty neat! A treat to see something historical. That said, I wonder if the 50,000 won is due to be demonetized one day?
I doubt that they'll get rid of the 50,000-Won note. I think that Korean people love that higher-value note as wedding gifts and graduation or birthday money. And gamblers and gangsters love it even more! Before that note came along, they would just use piles of 10,000-Won notes, or even use high-value foreign notes, like the U.S. $100. Now that they've had a higher-value note for over a decade, I don't think they'll get rid of it. This whole cashless scheme, while it may still come about, will have to allow for some use of cash, I think. Remember, the cashless society of 2020 is "a government plan." Other "government plans" included an ebook reader in every student's hand and a robot in every house. Those were actual S. Korean government plans! Needless to say, they never came about... So will some notes get withdrawn and demonetized? Only time will tell.