MIYADA, Nagano Prefecture—Despite being startled awake by horrific nightmares of World War II, Hideo Shimizu remained silent about what he had witnessed.

And even after innocent pictures of his grandchildren and great-grandchildren triggered gruesome memories of death and torture, Shimizu kept following orders to never break three vows of secrecy.

But one day in August 2015, 70 years after the war ended, the now 93-year-old resident here couldn’t contain his emotions.

He was with his wife at an exhibition themed on wartime relics, and a photo on display showed a large brick building.

Shimizu found himself explaining to his wife more details about the building than what the museum offered.

The building was the headquarters in China of the Imperial Japanese Army’s Unit 731. And Shimizu finally told his wife that he had been a member of the infamous biological warfare unit that used prisoners as guinea pigs in its experiments.

ASSIGNED AT 14

After graduating from a higher elementary school in March 1945, Shimizu was encouraged by his former teacher to work in Manchuria.

The former mentor had approached students who liked arts and crafts, and Shimizu thought they would be dispatched to a munitions factory.

Shimizu and five others from Miyada village took a train from Shiojiri in Nagano Prefecture to Nagoya.

They survived a U.S. air raid in Maibara, Shiga Prefecture, before traveling to the Korean Peninsula from the Hakata district in Fukuoka.

The boys were put on a truck in Harbin and taken to a large brick building in a suburban area that housed the Epidemic Prevention and Water Purification Department of the Kwantung Army, or Unit 731.

It was the building that Shimizu would see in the museum picture in 2015.

Shimizu, who was 14 years old at the time, and 34 boys of similar age made up the fourth group of minors assigned to Unit 731.

For about 10 days, they were told to memorize “Senjinkun” (instructions for the battlefield), a military code that stated, “Never live to experience shame as a prisoner.”

Shimizu was assigned to an education department laboratory where he studied pathogens, including how to cultivate them.

He was once told to collect germs from a mouse’s behind with what appeared to be a platinum earpick. He then inoculated the germs on gelatin in Petri dishes.

Shimizu was only allowed to move back and forth between the laboratory and his barracks.

He had to work in utmost secrecy and couldn't share details about his assignments even with colleagues who lived in the same building.

He had no idea what other sections were doing, and he was never told the names of soldiers, doctors and engineers with whom he interacted on a daily basis.

SPECIMEN ROOM

Shimizu still has nightmares about one day in July, when he was taken to a specimen room inside the auditorium on the second floor of the headquarters building.

The room was lined with jars, some as tall as an adult.

They contained human body parts preserved in formalin, including heads and hands.

An accompanying member only said they were from dissected “maruta.”

Shimizu had learned that the word, which means “logs” in Japanese, was a dehumanizing term for prisoners.

There was also the body of a pregnant woman with a big belly, whose lower part was laid open to display a fetus with hair.

It was the first time Shimizu had seen human bodies, and he couldn’t stop shedding tears.

The accompanying member didn’t say anything.

Shimizu’s days with Unit 731 didn’t last long because Soviet forces invaded the former Manchuria in the following month of August.

On Aug. 12, Shimizu was ordered to pick up the bones of prisoners in a prison called “Maruta Goya” (log cabin).

He collected bones from at least 100 prisoners whose bodies had been burned in a pit dug in the courtyard.

Shimizu and four other colleagues also carried defused bombs into Maruta Goya, which were then blown up by engineers.

He later realized that he had been made an accomplice of the unit’s efforts to destroy evidence.

When he boarded a retreating train, he was given a cyanide compound and told to kill himself rather than be captured.

He also learned that a close acquaintance who was an older member of the unit was “disposed of” with a cyanide compound while being treated for appendicitis.

After he returned to Japan, Shimizu never talked about what he saw or heard in former Manchuria.

When he was discharged from the Imperial Japanese Army, he was strictly ordered to keep three vows: hide your military record; never take public office; and never contact other unit members.

Lacking even a high school diploma, Shimizu had difficulty finding employment.

He worked with his carpenter father for 10 years and then qualified as an architect.

He married and was blessed with grandchildren and great-grandchildren.

But his emotional wounds never healed.

The nightmares of the bodies from the specimen room kept haunting him, and the photos of his grandchildren and their children at the entrance of his house caused flashbacks of the fetus preserved in formalin.

He could not hold back his tears.

But he still could not bring himself to talk about his experiences, even to his family, until that visit to the museum.

'LYING OLD MAN'

After Shimizu revealed his secret past to his wife, he decided to share his stories with the public.
He started discussing his wartime experiences at lectures in Miyada, and he soon caught the media’s attention.

One day, Shimizu found a blog entry that said: “This old man is telling lies. Or else, he doesn’t actually exist.”

Shimizu printed and laminated the blog page. He was filled with resentment every time he saw it.
He also read a book that claimed Unit 731 was a “hoax.”

Shimizu said he felt like his experience was being denied, and that certain people were intent on distorting historical facts.

In May last year, a peace memorial museum opened in Iida, also in Nagano Prefecture.

It was expected to show panels about Unit 731, including some featuring testimonies by Shimizu. But the plan was abandoned.

The city’s board of education, which runs the museum, said it needed to carefully consider the issue because academic research is still being conducted on Unit 731, and diverse opinions on the matter exist in society.

For Shimizu, it sounded like nothing but the don’t-rock-the-boat attitude.

He feels a strong sense of crisis about the current situation.

“They don’t know what horrible things Japan did to people in another country,” Shimizu said. “No matter what people say to me, I must keep telling the truth, otherwise future generations will be deprived of a chance to learn about it.”