Japan Trade More Specifically with Korea

Macro analysis of Japanese trade in posts Japanese Trade and the Yen and Japan Trade by Geographic Region revealed some very interesting changes.  Since the Korean Won is so undervalued versus the Japanese Yen on a Purchasing Power Parity (PPP) basis, I was very interested in how this undervaluation might have affected Japanese and Korean trade between themselves and with the United States.  The 2008-2009 financial crisis ended the growing Japanese surplus with Korea, and currently the Japanese surplus with Korea is at its lowest level since January 2003.

From TimelyPortfolio

When we look at the Japanese and Korean deficits with the United States, we can see Korea has maintained the level of surplus achieved prior to the 2008-2009 financial crisis, while the Japanese surplus has eroded rapidly over that same time frame.

From TimelyPortfolio

If the Korean Won appreciates versus the Yen, will Korean exporters maintain their recent market share gains?  If the Korean Won appreciates versus the Yen, will there be any impact on the US $?  If there is unexpected inflation, will this exacerbate the Korean Won appreciation?

R Code from GIST: