The ravages of World War II spread across the globe, touching almost every continent. And though the war ended more than 70 years ago, its ghosts linger on for some of its oldest victims.

Zhang Xiantu rests on a traditional brick bed in her house in Xiyan Town, Shanxi Province, China. Zhang was 16 years old, and recently married, when Japanese soldiers broke into her home and seized her. She couldn't run away because her feet were bound. Zhang, who died in November 2015, was the only surviving comfort woman of the 16 plaintiffs in Shanxi who sued the Japanese government in 1990s. Their claims were denied. | July 18, 2015 | (REUTERS/Kim Kyung-Hoon)

In the early 1900s and up through the end of World War II, Japan deployed its military across Asia in an attempt to expand its power and resources in the Pacific. In occupied Chinese and Korean territories, authorities kept aggressive troops "in check" by recruiting, tricking, and outright kidnapping women and forcing them into brothels run by the Japanese military. Exact numbers of the enslaved women, called "comfort women," a euphemism for forced prostitution, are hard to come by and estimates range from 20,000 to 200,000 women. Most of these women died. And in the messy period after Japan's surrender at the end of World War II, the survivors, some of whom were just teenagers when they were kidnapped, hid their past to protect their family, find a husband, build a life, and start again.

A former fortress, now abandoned, where Japanese soldiers kept women they abducted, in Xipan village, Shanxi Province. | July 18, 2015 | (REUTERS/Kim Kyung-Hoon)

In China, the survivors and their stories might have just faded into obscurity if it hadn't been for a few dedicated activists and lawyers who located about 20 living Chinese comfort women. Over the decades, they have been working on the women's behalf to secure compensation and a formal apology from the Japanese government. But due to the shifting and often tumultuous political relationship between Japan and China, the remaining Chinese victims, fewer in number every year, have so far been denied reparations.

In South Korea, a more organized political movement has helped surface more than 238 victims over the years, a fraction of whom are still alive today. In the 1990s, Japan issued an apology and set up a private fund for survivors in South Korea, but the government and many of the victims largely rejected it. In December 2015, Japan and South Korea reached a new landmark agreement that included an apology and a promise of $8.3 million paid to the women by the Japanese government. While the deal has been praised by U.S. Secretary of State John Kerry, among others, as a step toward mending the equally fraught relationship between the two countries, many of the comfort women, as well as the Chinese activists fighting for their own agreement, remain critical.

In the summer of 2015, Reuters photographer Kim Kyung-Hoon visited some of the remaining Chinese and South Korean comfort women. Below, a look at his beautiful and emotional portraits of the survivors in their homes.

Ren Lane at her house in Gucheng Town, Shanxi Province, China. According to her statement, Ren was abducted by Japanese soldiers when she was 15 years old. | July 17, 2015 | (REUTERS/Kim Kyung-Hoon)

Hao Juxiang, 92, in her house in Gucheng Town, Shanxi Province, China, was either 15 or 16 years old when she was abducted. | July 16, 2015 | (REUTERS/Kim Kyung-Hoon)

Hao Yuelian, in her home in Taiyuan, Shanxi Province, China, was taken by Japanese soldiers when she was 17. Hao was never able to have children of her own, something her family blames on her treatment in the brothels, but later adopted a daughter. | July 16, 2015 | (REUTERS/Kim Kyung-Hoon)

Lee Oksun lives in a special shelter for former comfort women in Gwangju, South Korea. According to her testimony, Lee was 15 when she was taken from South Korea to an airfield in China, where she was habitually raped, and then moved to various Japanese military brothels. | July 24, 2015 | (REUTERS/Kim Kyung-Hoon)

Kim Bokdong holds her painting, titled "The Day a 14-year-old Girl is Stolen Away," in her room in a shelter for former comfort women in Seoul, South Korea. According to her testimony, Kim was taken to multiple Japanese military brothels in China, Malaysia, and Indonesia, from 1940 until Japan's surrender in 1945. She said that on the worst days, she was forced to have sex with what "seemed like more than 50" Japanese soldiers. | July 23, 2015 | (REUTERS/Kim Kyung-Hoon)

Gil Wonok sits in her room in a shelter for former comfort women in Seoul, South Korea. According to her testimony, Gil was taken to a military brothel in China in 1940, where she caught syphilis and developed tumors. A Japanese military doctor eventually removed her uterus leaving her unable to bear children. | July 23, 2015 | (REUTERS/Kim Kyung-Hoon)

A memorial wall commemorating Korean comfort women at the War and Women's Human Rights Museum in Seoul, South Korea. | July 22, 2015 | (REUTERS/Kim Kyung-Hoon)