Between 1932 and 1945, hundreds of thousands of women and girls across Asia were forced into sexual slavery by the Imperial Japanese Army.
Referred to as "comfort women", they were taken from countries including Korea, China, Taiwan, the Philippines and Indonesia to be raped by Japanese soldiers.
Today, the issue remains a source of tension between Japan and its neighbours, with continuing campaigns to compensate the few surviving victims.
Dan Hardoon speaks to Chinese survivor Peng Zhuying who, along with her elder sister, was captured and taken to a "comfort station" in central China.
This programme contains disturbing content.
(Photo: People visit a museum dedicated to the victims, on the site of a former comfort station in China. Credit: Yang Bo/China News Service/VCG/Getty Images)