South Korea and Japan are trying to put past friction behind them:
In the first bilateral talks between the two countries since 2012, South Korean President Park Geun-hye and Japanese Prime Minister Shinzo Abe agreed to speed up the resolution of the “comfort women” dispute, according to Reuters[.]
"Comfort women" were Korean sex slaves for Japanese troops occupying Korea. It was an ugly business. And the Japan of that era was brutal.
But Japan is different now. And China looms over both. Best to settle this dispute so that it doesn't hinder military and political cooperation.