Cited from BBC ;
What has made it fester is the belief that Japan has never fully owned up to its atrocities in places it occupied – not just China, but also Korea, what was then Malaya, Philippines, Indonesia. One of the most painful points of contention involves "comfort women" - the approximately 200,000 women who were raped and forced to work in Japanese military brothels.

You crucially are  mistaken because Korea completely was the part of Japan at those days. 
As the natural results, 
1. About twenty The Koreans in so-called "Kamikaze attacking" was died.
2.During World War II, approximately 240,000 soldiers from the Korean Peninsula participated in the Japanese army, including both volunteers and conscripts, and a great majority of Korean soldier (=The Japanese soldier) was the sentry at POW camp. 
3.Therefore, 148 The Koreans soldier(=The Japanese soldier) were convicted as war criminal 

Needless to say, Japan invaded China, Philippines, Malaysia, and Indonesia, however Korean peninsula at that time completely was within Japan.

To my knowledge, 
1.about half of the brothel owners were The Koreans (=The Japanese)  at Japan-China war.
2. so-called "sex slaves" might include The Chinese and Filipinos,  but The Japanese women (=The Koreans women) definitely was not include.
3.accoding to testimonies published in South Korea of  "comfort women", more than half of  "The Koreans comfort women" testified that we are deceived that you can work in mainland Japan.
4.It is historical fact that "comfort women" received fair consideration from the soldiers in exchange for prostitution, with the owners taking half and the women receiving the other half.

it is  complete misunderstanding !. only one word, Korean peninsula was the Japan.