A former sex slave for Japanese troops during World War II died Sunday, bringing the total number of living South Korean victims of the atrocity to 55.

Hwang Kum-ja died of old age at a hospital in Seoul, an activist group said. She was 90.

Hwang, who was born in 1924, was forced into a glass factory at age 13 and then transferred to China for sexual slavery three years later. She came back home after Korea was freed from the 1910-45 colonial rule but lived alone for the rest of her life.

Hwang made a living on government subsidies and money earned from collecting garbage. Still, she made three donations to a scholarship fund that totaled 100 million won ($92,635).

She received a state medal in 2011 for such good deeds.

Hwang left a wish that she would donate all of her remaining assets worth some 30 million won to charity.

Historians say up to 200,000 women, mostly Koreans, were coerced into sexual slavery at front-line Japanese military brothels during the colonial rule.

South Korea has urged Japan to resolve the grievances of the victims, saying the issue is becoming increasingly urgent as most victims are elderly, well over 80 years old, and may die before they receive compensation or an apology from Japan.

Japan has snubbed Seoul's demand for official talks on compensating the aging Korean women, claiming all issues regarding its colonial rule were settled in a 1965 package compensation deal under which the two countries normalized their relations. (Yonhap News)