Noel Celis/AFP/Getty Images A Filipina "comfort woman" wipes away a tear during a January protest in Manila. Over 1,000 women and girls were captured and imprisoned in "rape camps" in the Philippines by the Japanese military during World War II.

It has taken M. Evelina Galang almost 20 years to chronicle one of her nation's greatest traumas. It's the story of how women finally broke their silence in the wake of war and terror; a testament to their courage and their long-buried grief.

“I've been writing this book for a lifetime,” said Galang, 55, a Filipina-American novelist, essayist and educator.

In her unpublished manuscript Lolas’ House: Survivors of Wartime Rape Camps, Galang tells the often overlooked story of the hundreds of Filipina women who were forced into sexual slavery by the Japanese military during World War II.

“These ‘comfort women’ were mostly 13, 14, 15 years old. They weren’t really women, they were girls,” Galang said of the victims, who are now so old they're respectfully referred to as “Lolas,” the Tagalog word for grannies. “They were forced to do labor and raped up to 20, 30 times a day, every single day. The tragedy is colossal.”

Since 1998, Galang, the director of the creative writing program at the University of Miami, has been traveling to and from the Philippines to gather testimonies for her book. To date, she's recorded more than 40 hours of interviews with 15 Lolas, spent weeks visiting with the women and their families, and even traveled around the country with seven of them, bringing them back to the sites of their abduction and imprisonment.

“The stories poured out of the Lolas like water from a dam,” Galang said of the meetings. “Horrific testimonies of habitual rape and torture.”

M. Evelina Galang Writer M. Evelina Galang poses behind Piedad Nobleza, Dolores Molina and Josefa Villamar on July 12, 2007. The three women survived imprisonment by the Imperial Japanese Army during World War II.

Prescilla Bartonico was 17 when she was captured by the Japanese.

The year was 1943. Bartonico and a younger cousin were cowering in an air raid shelter on the Filipino island of Leyte with family members and neighbors; the sounds of gunfire and bomb blasts punctured the still air.

The door banged open and soldiers from the Imperial Japanese Army were suddenly upon them. They grabbed Bartonico’s cousin and dragged her across the floor. The girl screamed and kicked and scratched the soldiers’ faces. Three soldiers took turns raping her before they killed her.

Witnessing her cousin's assault and murder, Bartonico wept as another soldier tied her up and raped her in front of her family and friends. “I wanted to resist, but I was too afraid,” she said. “[So began] my suffering ... at the hands of the Japanese soldiers.”

These 'comfort women' were mostly 13, 14, 15 years old. They weren’t really women, they were girls. M. Evelina Galang, Filipina-American author

For the next three months, Bartonico was imprisoned in a military garrison in the town of Burauen in the Philippines. She said she was raped multiple times daily, “by five to eight” men.

“[It was] mostly during nighttime because we were forced to work in the landing field during the day,” she said of those dark days. “Sometimes, they even brought us to the guard posts where they kept their machine guns in trenches made up of sacks filled with soil.”

An estimated 400,000 women and girls across Asia were abducted and forced to serve in so-called “comfort stations” by the Japanese military during World War II. A majority of these victims were taken hostage in South Korea and China, but women were captured in virtually every territory occupied by the Japanese, including Taiwan, Indonesia, Malaysia and Indonesia.

In the Philippines, researchers estimate that more than 1,000 girls and women were sexually enslaved by the Japanese during World War II.

Today, only 70 of them are still living.

M. Evelina Galang Prescilla Bartonico was held captive by the Japanese army for three months in 1943. She told Galang that she was never able to sleep a full night after her imprisonment, so she'd paint murals using tissue, cardboard and children's tempera paints while her family slept. Here, she smiles in front of one of her creations.

Bartonico died in 2006. She did not live to see an apology or recognition from the Japanese government for the trauma she lived through.

But she did share her story.

“Every time a Lola gave her testimony, she relived that experience. She’s not talking about the past. She’s in it all over again,” said Galang, whose book includes Bartonico's account of the war. “When I ask the Lolas why they have come forward, they have two reasons. First, they are standing up for themselves and they are demanding justice. Secondly, they tell me, ‘So it won’t ever happen again.’”

For the women, sharing their stories was akin to reliving their torment, but receiving the women's testimonies brought its own trauma, Galang said.

The writer recalled the first time she interviewed the Lolas for her book. She and one of her students spoke to several of them, one after the next.

“At the end of the day, Ana Fe and I were swollen from all the tears,” Galang remembered. “One of the Lolas said, ‘The stories have entered their bodies.’”

Galang would later be reminded of those words as she sat down to start writing her book.

“When I first started writing, I would grow tired after two hours and I’d have to stop,” she said. “I can sit before a screen for an entire weekend and write a novel or a short story. But these stories of the Lolas? At first I’d sit down to go through the transcriptions, or to write an essay and I would fall asleep right in front of my computer. I noticed a strange fatigue that would come over me. And then I remembered what the Lola had said: ‘The stories have entered their bodies.’”

M. Evelina Galang M. Evelina Galang marches with the Lolas at an International Women's Day protest in 2002.

It took fifty years before the Lolas' stories came to light.

In 1993, Rosa Maria Henson became the first Lola to come forward publicly about her experience. Henson had been 15 when Japanese soldiers abducted her. They incarcerated her for 9 months, and up to 30 men raped her every day.

“I lay on the bed with my knees up and my feet on the mat, as if I were giving birth. Whenever the soldiers did not feel satisfied, they vented their anger on me. When the soldiers raped me, I felt like a pig,” Henson, who died in 1997, described in her memoir. “I was angry all the time.”

For decades, no one except Henson’s mother knew about those days of abuse. Even Henson’s husband and her children had been kept in the dark.

“I am telling my story so that they will feel humiliated,” Henson said of the soldiers who raped her, according to a New York Times obituary. “It is true: I am an avenger of the dead.”

Romeo Ranoco/Reuters Rosa Maria Henson (second from left), from the Philippines, joins Korean "comfort women" Kim Soon Duk (left) and Yoong Sue Ree (second from right) during a protest rally staged in front of the Japanese embassy in Manila in 1996. Henson died a year later.

Inspired by Henson, 174 other Filipina women eventually came forward to share their stories.

“The culture of 'tsisimis’ and 'hiya’ -- shame and gossip -- is strong in Filipino society. When word got out that a woman was a ‘comfort woman,’ she might have been called 'tira ng hapones,’ or 'Japanese leftovers,'” explained Galang. “Some women were not taken back by their families after the war. Some Lolas who came forward had to deal with their sons and daughters and even husbands who got mad at them for speaking their truth."

Piedad Nobleza described how her aunt had "shot [her] a look" after she'd arrived home following weeks of sexual enslavement.

“She did not say anything at all,” Nobleza told Galang. “I sat in the corner, crying and crying.”

Nobleza was captured by Japanese solders in 1942. She was dragged to a church near her home where she was raped by multiple men.

"That first night, the soldiers placed two pews together. Two of them argued who would go first. The first soldier was fair, not too tall, and not too fat," Nobleza recalled. "After that, seven Japanese soldiers raped me. They came every half hour. And after that, every night for two weeks, two or four soldiers raped me every night."

Nobleza told Galang that she felt an obligation to share her story with the world. “Young girls need to know what happened,” she said.

"So many of [these] stories were held in the women’s bodies for fifty years," said Galang. "A few of the women said when she told her story, 'Nabawasan ang dibdib ko.’ That phrase is hard to translate, but it means something like her heart grew lighter, the pain was less.”

Aaron Favila/Associated Press Piedad Nobleza, then 86, holds slogans during a demonstration outside the Japanese Embassy in suburban Manila on Friday Aug. 15, 2008.

The Japanese government has long contested the stories of rape told by Nobleza, Henson, Bartonico and the thousands of other comfort women across Asia.

In 2007, Japanese Prime Minister Shinzo Abe controversially claimed that “there was no evidence to prove” that the women had been coerced into sex. A few years later, Abe's name appeared in an advertisement in New Jersey's Star-Ledger newspaper protesting a memorial to the comfort women erected in Palisades Park, New Jersey. Abe was listed as one of the "assentors" to the ad, which called the stories of the comfort women a "fabrication of history."

“The government of Prime Minister Shinzo Abe is engaged in an all-out effort to portray the historical record as a tissue of lies designed to discredit the nation," wrote Mindy Kotler, director of Asia Policy Point, in 2014.

“Mr. Abe’s administration denies that imperial Japan ran a system of human trafficking and coerced prostitution, implying that comfort women were simply camp-following prostitutes,” Kotler continued. "The official narrative in Japan is fast becoming detached from reality, as it seeks to cast the Japanese people -- rather than the comfort women of the Asia-Pacific theater -- as the victims of this story.”

The Japanese Embassy did not return a request for comment from The Huffington Post.

Last year, after years of diplomatic pressure from Seoul, Japan offered a formal apology and the promise of an $8.3 million payment to Korean women forced into sexual servitude during the war. In return, South Korea agreed to never raise the issue again -- so long as Japan also honors the accord.

The Japanese government is doing their best to erase history. They say there is no evidence, but I have heard the evidence, I have touched the evidence. M. Evelina Galang

But closure has hardly been reached. Just two months after the accord, Japan’s deputy foreign minister, Shinsuke Sugiyama, told a U.N. panel in Geneva that there was no proof that the Japanese military or government forced the women into sex, prompting rage from South Korea.

Activists have also insisted that the Seoul-Tokyo agreement did not go far enough, and that the wishes of the Korean comfort women themselves had not been taken into consideration during the negotiations.

Moreover, for comfort women in the Philippines and elsewhere, there have been no signs of an official apology or compensation from Tokyo.

“The Japanese government is doing their best to erase history,” said Galang. “They say there is no evidence, but I have heard the evidence, I have touched the evidence. When I spoke to the Lolas, they would take my hand and bring it to wounds on their body -- places they were hit by the soldiers or cut by knives, cigarette burns, bumps, scars and bruises.”

Noel Celis/AFP/Getty Images Lolas protest near the Malacanang Palace in Manila, where visiting Japanese Emperor Akihito met President of the Philippines Benigno S. Aquino III on Jan. 27, 2016.

Noel Celis/AFP/Getty Images A protesting woman wipes away tears during Japanese Emperor Akihito's visit to Manila.

In January, when Emperor Akihito of Japan visited the Philippines, the few surviving Lolas gathered for peaceful protests in Manila. Now in their 80s and 90s, the women -- some of them leaning heavily on walking sticks, their bodies hunched with age -- stood in the blazing sun, chanting slogans and holding signs with the words “justice” and “historical inclusion” emblazoned on them.

But though the emperor, during his meeting with Filipino President Benigno S. Aquino III, did speak about the atrocities committed by the Japanese military during World War II, the comfort women were ignored.

“I was happy for the emperor’s visit because I thought he could bring justice for us,” 89-year-old Hilaria Bustamante, who was kidnapped at the age of 16, told The New York Times. “But he never mentioned us.”

Telling the Lolas' stories now, said Galang, is critical.

She hopes some of the elderly victims might themselves see justice in their lifetime (almost all the Lolas interviewed for her book are now dead), but she also believes that the women's testimonies are lessons deeply relevant to this age -- an era when thousands of women in Democratic Republic of Congo are raped every year, and America's schools and colleges struggle with a scourge of sexual violence.

“The ‘comfort woman’ issue goes beyond a history lesson, but is in fact an extension of our conversation about women and their bodies today,” Galang said. “This story is happening now. It’s happening in part because we have chosen not to hear the grandmothers. The Lolas’ stories, their experiences in wartime rape camps, and their fight for justice is a legacy to all women. What happened to them is happening now to women in Syria, in Bosnia, in the Congo, and on college campuses in the United States.”

“It seems to me that we have a culture where raping women and girls is not taken seriously,” she added. “We, as a global culture, need to stand up and say 'No. Stop. Not right.' Until we do, this history repeats itself. We need to document their stories. We need to understand their place in history. We need to make sure it never happens again.”

Dondi Tawatao/Getty Images Lolas protest in front of the Japanese Embassy on August 14, 2015.

Dondi Tawatao/Getty Images Remedios Pecson holds a sign at a protest in front of the Japanese Embassy on Aug. 14, 2015. Pecson, then 80 years old, carried a walking stick and was supported by fellow protesters during the rally.

AP Photo/Aaron Favila Narcisa Claveria, 86, calls for justice during a protest in front of the Japanese embassy in Manila on March 1, 2016.

"Lolas’ House: Survivors of Wartime Rape Camps" is under consideration with a U.S. publisher. Find out more about the Lolas and Galang's book at the author's blog and website.