I was in New Jersey yesterday and decided to stop by the place where a plaque stood for 'comfort women' during Japan's capture of Korea. I remember some uncles talking about these women and their prevalence during the Korean War. Supposedly, some were tricked into prostitution while others went willingly because the pay was good (or better than poverty). Also, according to this wiki page (link) it appears that the first such women were Japanese prostitutes. But demand was so great that the Japanese military began getting its supply from local pimps in China and Korea. So, it appears as if abuse by locals has been added to the category of supposed war crimes by Japan.