Female Japanese POWs Were Shocked by Sanitary Napkins — Had Never Seen Them

August 17th, 1945.

Prisoner Processing Center, Guam.

Lieutenant Yamamoto Sachiko of the Imperial Japanese Army Nurse Corps stood frozen in the supply line, staring at the small rectangular package the American Medical Corman had just placed in her hands.

The rapper featured English text she couldn’t fully read, but the illustration was clear enough.

a smiling woman in white holding what appeared to be a thick pad of cotton wrapped in gores.

“What is this?” she asked in halting English, her voice barely above a whisper.

The American nurse, First Lieutenant Margaret Hayes of the Army Nurse Corps, looked momentarily confused by the question.

“Those are sanitary napkins, Mom.
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Cotex brand.

You’ll receive a box of 12 every month along with your other hygiene supplies.

Yamamoto turned the package over in her hands, examining it with the clinical precision her medical training had instilled.

The wrapper promised 8-hour protection and comfortable fit.

The product inside felt thick, soft, and incredibly absorbent.

She had been a military nurse for four years, had treated thousands of wounded soldiers, had performed amputations under artillery fire.

But this small package represented something she had never encountered in all her medical training.

A disposable, mass-produced solution to a problem Japanese women had managed with folded cloth, paper, and endurance for thousands of years.

What Lieutenant Yamamoto didn’t know, what none of the 347 Japanese women being processed as prisoners of war that day could have known, was that this small package represented an industrial achievement that would fundamentally alter their understanding of American society.

The Cotex company had produced over 85 billion sanitary napkins since 1921.

America manufactured more disposable menstrual products monthly than Japan had produced in its entire history.

This wasn’t just abundance.

This was a civilization that had industrialized even the most intimate aspects of women’s health, creating mass production solutions that most of the world, including Japan, had never imagined possible.

To understand the shock these Japanese women experienced, one must first understand what they had known.

In wartime Japan, women’s menstrual management had remained essentially unchanged for centuries.

The standard method involved folded cotton cloth washed and reused repeatedly until the fabric disintegrated.

Urban women with resources might use multiple layers of clean cotton.

Rural women often relied on old cloth, newspaper, or in desperate circumstances, nothing at all.

Captain Tanaka Miko, a military nurse captured on Saipan, would later describe the Japanese reality to American intelligence officers.

“We used cotton cloth folded many times,” she explained through an interpreter.

“Each woman kept several pieces in her personal belongings.

When needed, you folded the cloth, placed it inside your undergarments, and changed it every few hours.

After use, you washed it thoroughly, boiled it if possible to sanitize, and dried it for reuse.

This was normal.

This was what our mothers taught us, what their mothers taught them.

The system, while traditional, created constant difficulties.

Military nurses working 12-hour shifts, couldn’t always excuse themselves to change cloths.

Washing facilities in field hospitals were limited.

Privacy was nearly non-existent.

During combat operations or while treating casualties, nurses often worked through their periods with inadequate protection, experiencing discomfort and embarrassment they considered part of their duty.

By 1945, wartime conditions had made even this basic management nearly impossible.

Cotton was rationed for military bandages.

Soap was scarce.

Hot water for boiling cloth was a luxury.

Many women resorted to using rough paper, dried moss, or layers of whatever fabric they could find.

Some simply endured their periods without any protection, accepting the inevitable staining and discomfort as unavoidable wartime hardship.

Enen Kobayashi Yuki, a naval communications officer captured in the Philippines, recalled the desperation.

In the final months before capture, we had no cotton, no clean cloth, nothing.

I used torn pieces from my spare uniform, washed in cold water when I could find water at all.

Sometimes I couldn’t wash them for days.

The shame was terrible, but there was no choice.

We were told such sacrifice was our duty to the emperor.

The American reality these women encountered at the P processing centers seemed impossible.

Not only did disposable sanitary napkins exist, but they were provided free to prisoners, enemies who had fought against America.

The cognitive dissonance was overwhelming.

The Cotek sanitary napkin had been invented in 1920 by Kimberly Clark, adapting cellucotten bandage material developed during World War I.

By 1921, the company was advertising nationally, breaking taboos about discussing menstruation publicly.

By 1945, Cotex dominated the American market, producing millions of sanitary napkins monthly in factories across the United States.

The manufacturing process represented mass production sophistication the Japanese industry had never achieved for consumer products.

At the Nenina, Wisconsin plant, the largest Cotex facility, automated machines produced 4 million napkins daily.

Cellic cotton, a wood pulp derivative far more absorbent than cotton, was pressed into pads, wrapped in gauze, and packaged in individual wrappers.

The entire process, from raw material to finished product, took less than 3 hours.

Each napkin contained approximately 15 g of cellucotton compressed to optimal density for absorption while maintaining comfort.

Testing had determined the exact thickness, length, and width for maximum effectiveness.

American engineers had literally turned menstrual protection into a science, applying industrial efficiency to a problem most societies considered too private to address publicly.

By 1945, American women consumed approximately 3.5 billion sanitary napkins annually.

Cotex, Modest, and other brands competed for market share through advertising in women’s magazines, radio commercials, and even educational films shown in schools.

The products were available in every drugstore, grocery store, and five and dime across America.

They cost between 25 and 35 cents per box of 12.

affordable for working women who earned several dollars daily.

For the Japanese women ps, the discovery came in waves, each revelation more stunning than the last.

The first shock was simply that such products existed.

The second was discovering they were disposable, used once and thrown away.

The third was learning they were mass-roduced by the billions.

The fourth and perhaps most psychologically significant was understanding that even enemy prisoners received them free.

At the women’s compound in Guam, American nurses conducted orientation sessions for the Japanese PSWs.

Lieutenant Sarah Morrison of the Army Nurse Corps led the first hygiene instruction, working through interpreters to explain American sanitary products to women who had never heard of such things.

These napkins are changed every 4 to 6 hours, Morrison explained, holding up a cotex pad.

You dispose of them by wrapping them in paper and placing them in the waste bins marked for sanitary disposal.

You’ll receive a fresh box of 12 each month or more if needed.

If you require additional supplies between distributions, simply request them from any nurse.

Through the interpreter, questions came rapid fire.

How could they just throw them away? Wasn’t that wasteful? Why not wash and reuse them? How did America have so many they could give them to prisoners? Morrison’s answers, translated carefully, revealed a world the Japanese women had never imagined.

America produced so many sanitary napkins that reusing them was considered unsanitary and unnecessary.

The cost of washing and drying would exceed the cost of manufacturing new ones.

Every American woman used disposable products.

This wasn’t special treatment for prisoners, but the basic standard even American school girls received.

Petty Officer Nakamura Ko, who had worked in naval communications, asked through the interpreter.

In America, even ordinary women can afford to throw away these products after one use.

Yes, Morrison replied simply, “Most American women wouldn’t consider using anything else.

Some brands are cheaper, some more expensive, but all are designed to be disposable.

The average working woman spends less than 1% of her monthly income on sanitary products.

The Japanese women exchange glances, struggling to process this information.

An ordinary American factory worker earned enough that spending 35 cents monthly on disposable menstrual products was insignificant.

In Japan, such products didn’t exist at any price.

The disparity revealed an economic gulf that ideology and propaganda had never prepared them to understand.

The first month of use brought practical revelations that deepened the psychological impact.

The Cotex napkins worked exactly as promised.

They were comfortable, absorbent, and eliminated the constant worry about leakage and staining that had plagued the women throughout their military service.

The security they provided was something none of them had experienced since childhood before they understood the monthly inconvenience as simply part of being female.

Warrant officer Suzuki Hanako, a senior military nurse with 8 years of service, found herself crying the first time she used a disposable napkin.

In her diary, kept secretly despite regulations and later preserved by American intelligence, she wrote, “Today I experience something I never knew existed.

Complete freedom from worry during my monthly time.

The American napkin is thick, soft, and I changed it after 6 hours without any leakage.

I simply wrapped it and disposed of it, then opened a fresh one.

No washing, no boiling, no fear of insufficient cloth.

For 20 years, I have managed my periods with anxiety and discomfort.

These American women have lived their entire adult lives without such worry.

What kind of society creates such solutions for women’s comfort? The industrial implications slowly became clear as the PS learned more about American production.

During work assignments at the camp, some Japanese women were assigned to the post exchange warehouse where supplies arrived.

They watched American service women purchase Cotex boxes casually, five or six boxes at once, storing them in their lockers for future use.

The abundance was casual, thoughtless, routine.

Sergeant Kimura Tomaco, assigned to warehouse inventory, began counting.

In one month, the Guam Naval Base PX received 847 cases of sanitary napkins.

Each case containing 48 boxes of 12 napkins.

That was 488,000 individual napkins for the approximately 3,000 American women stationed on Guam.

The math was staggering.

America was shipping half a million disposable sanitary napkins monthly to a single Pacific island for their own personnel while simultaneously supplying prisoners.

The ships carrying these supplies had traveled 6,000 mi from American factories to a forward combat zone alongside ammunition, fuel, food, and military equipment.

Sanitary napkins were considered essential enough to justify the cargo space, the shipping costs, and the logistics coordination.

Japanese military supply chains had struggled to provide ammunition to frontline troops.

American supply chains considered disposable menstrual products a priority item.

The educational materials provided to PS included American women’s magazines confiscated from service women’s quarters and deemed suitable for prisoner morale.

These magazines contained advertisements for cotex modes and other feminine hygiene products.

The advertisements were revealing, showing smiling women engaged in sports, dancing, working in offices, all supposedly made possible by superior menstrual protection.

One Cotex advertisement from a 1945 ladies home journal particularly fascinated the Japanese women.

It featured a woman in a tennis outfit with the headline, “Play through any day of the month.” The text explained that modern American women needn’t limit their activities during menstruation thanks to Cotex’s revolutionary protection.

The advertisement included a coupon for a free sample.

Lieutenant Yamamoto read and reread this advertisement trying to comprehend its implications.

American companies competed to provide better menstrual products.

They advertised openly in mainstream magazines, discussing a topic Japanese society considered too shameful to mention.

They encouraged women to maintain active lifestyles during their periods rather than accepting rest and limitation as natural.

The advertisement suggested that periods should be a minor inconvenience at most, not the significant burden Japanese women had always accepted as unchangeable reality.

The psychological transformation this created went beyond simple amazement at American abundance.

It challenged fundamental assumptions about women’s place in society, the priorities of industrial production, and the relationship between technological advancement and quality of life.

In traditional Japanese thinking, menstruation was considered polluting, something to be endured privately with minimum acknowledgement.

Women were expected to manage silently, never discussing it, accepting discomfort as natural.

The idea that industry should address this problem would have seemed bizarre, possibly shameful, certainly not a priority for serious manufacturing capacity.

American society, these women discovered, thought differently.

Not only had American industry created solutions, but American culture openly discussed and advertised them.

Teenage girls received education about menration in schools.

Mothers and daughters talked about which brands worked best.

Women shared advice about managing their periods during sports or work.

The whole subject, while not discussed crly, wasn’t shrouded in shame.

This cultural difference revealed something deeper about how each society valued women’s comfort and health.

For Japanese military nurse Lieutenant Yamamoto, the realization was profound.

She wrote in her diary, “The Americans have created an entire industry to address women’s monthly discomfort.

They dedicate factories, engineers, advertisers, and millions of dollars to this purpose.” What does this say about how they value women? Our society taught us to endure silently, that such matters were too shameful to address openly, that accepting discomfort was noble.

The Americans apparently believe women’s comfort matters enough to industrialize solutions.

I don’t know which approach is correct, but I know which one feels better.

The practical benefits extended beyond comfort.

American medical personnel noted that Japanese PSWs experienced significantly fewer menstrual related health issues once provided with sanitary napkins.

Infections decreased.

Anemia from excessive bleeding improved when women could change protection frequently rather than extending use of inadequate cloth.

Stress and anxiety related to menstrual management disappeared.

Captain Tanaka, the senior Japanese nurse, noticed the change in her fellow PWS.

Women who had been withdrawn and depressed became more energetic.

Those who had isolated themselves during their periods now participated in camp activities.

The simple availability of adequate menstrual protection had measurably improved morale and health.

In medical discussions with American nurses, Captain Tanaka learned even more surprising information.

American military women received not just sanitary napkins, but also menstrual pain medication, heating pads for cramps, and even excused duties for severe symptoms.

The American military acknowledged that menstruation could be debilitating and made accommodations accordingly.

This contrasted sharply with Japanese military policy, which officially didn’t acknowledge that female personnel menstruated.

There were no provisions, no accommodations, no supplies.

Women were expected to manage privately and continue all duties without complaint.

The unspoken message was clear.

Menration was a female weakness to be overcome through discipline and willpower, not a normal biological function deserving accommodation.

The comparison forced difficult questions.

Which approach treated women with more dignity? the Japanese system that expected silent endurance or the American system that provided industrial solutions.

The Japanese emphasis on stoic acceptance or the American focus on practical comfort.

Was American openness about menstruation shameless? Or was Japanese silence actually the shameful approach forcing women to suffer unnecessarily? As the months of captivity continued, the Japanese women ps learned more about the American feminine hygiene industry.

Educational materials included information about the manufacturing process, the competing brands, and the marketing strategies.

This education wasn’t intended for the prisoners originally, but American authorities decided that understanding American industry might aid in postwar reconstruction attitudes.

The scale of production was difficult for the Japanese women to comprehend.

The Cotex company alone operated 11 factories across the United States by 1945.

Each factory employed hundreds of workers, mostly women, who earned competitive wages with benefits, including paid menstrual leave.

The largest facility in Nenina, Wisconsin, covered 40 acres under one roof, contained 247 production machines, and operated 24 hours daily.

The raw materials came from American forests where fast growing pine trees were harvested, processed into wood pulp, and converted into cellar cotton through chemical treatment.

The seller cotton was formed into pads wrapped in gores made from cotton grown in southern states and packaged in paper printed with instructions in multiple languages for international sale.

Every aspect of the process had been optimized for efficiency.

Time motion studies determined the fastest way to fold the gores.

Chemical engineers improved the absorbency of cellucotton.

Industrial designers created packaging that protected the product while minimizing material use.

Marketing researchers studied women’s preferences and designed products accordingly.

This industrial sophistication applied to sanitary napkins seemed almost comical to the Japanese PS initially.

Americans had weaponized engineering and manufacturing expertise normally reserved for military equipment and applied it to feminine hygiene.

But the more they learned, the less comical it seemed and the more it represented something profound about American society.

Enen Kobayashi, who had studied engineering before the war, became fascinated by the technical aspects.

She obtained permission to examine the Cotex napkins scientifically, dissecting them to understand their construction.

What she discovered amazed her.

The napkin consisted of three layers, each engineered for specific purposes.

The top layer was soft gauze designed for comfort against skin.

The middle layer was compressed cellucotton with aligned fibers that wicked moisture inward and distributed it evenly to prevent heavy spots.

The bottom layer was slightly waxed gauze that provided a moisture barrier while remaining breathable.

The pad was tapered at the ends to prevent bunching, had rounded corners to prevent irritation, and was precisely 10 in long by 3.5 in wide at the center, dimensions determined through research on optimal coverage.

The engineering was sophisticated, more complex than many pieces of military equipment she had worked with.

Americans had applied serious scientific methodology to understand the fluid dynamics of menstrual flow, the materials science of absorbent compounds, and the ergonomics of comfortable fit.

They had invested research dollars, engineering hours, and manufacturing capacity into perfecting a disposable product used for a few hours and thrown away.

In her technical report written partly as therapy and partly as documentation, Kobayashi concluded, “The American sanitary napkin represents industrial philosophy fundamentally different from Japanese thinking.

We would consider such investment in a disposable product wasteful.” Americans apparently calculate that women’s comfort and health justify sophisticated engineering and manufacturing cost.

The napkin I examined demonstrated quality control equal to precision military components, every dimension exact, materials consistent, construction flawless.

This suggests American industry applies the same standards to consumer products as military equipment, a practice we never attempted.

The cultural education continued through interaction with American service women stationed at the camps.

These young American women, many barely 20 years old, treated sanitary napkins with complete casualness.

They discussed brands with the same enthusiasm.

They discussed lipstick or shoes.

They traded them like currency, loaning boxes to friends who ran short.

They complained about pricing, debated which brand was best, and shared tips for comfort.

This casual openness about menration shocked the Japanese women initially.

Such discussions would be considered vulgar in Japanese society, something whispered about if discussed at all, never mentioned in mixed company or even openly among women.

But the American women seem to consider menration as mundane as any other aspect of hygiene worthy of practical discussion but not shame or secrecy.

Private first class Dorothy Chen, a Chinese American serving as an interpreter, helped bridge this cultural gap.

She explained to the Japanese PWS that American girls learned about menstruation in school health classes, received free samples of sanitary napkins to try and were encouraged to tell their mothers or teachers if they had problems.

The whole process of managing periods was treated as a normal skill to learn, like learning to brush teeth or wash hair.

This educational approach contrasted dramatically with Japanese practice where girls learned about menstruation from whispered conversations with mothers or older sisters, received minimal instruction in managing it, and were expected to figure out solutions privately.

The shame and secrecy surrounding menstruation meant many Japanese girls experienced their first period with terror and confusion, believing something was terribly wrong with their bodies.

The American openness about menstruation extended to surprising areas.

Medical research into menstrual health was published openly in medical journals.

Companies funded research into better products.

Women’s magazines ran advice columns answering questions about periods.

Even male doctors specialized in women’s health, something unthinkable in traditional Japanese medical practice, where male doctors never examined women for such private matters.

This systematic, open approach to addressing women’s health needs revealed something fundamental about American society that the Japanese PS struggled to articulate but deeply felt.

America apparently believed that women’s comfort mattered, that their health deserved serious attention, that their biological functions should be accommodated rather than ignored.

Whether this made American society superior was debatable, but it certainly made American women’s lives more comfortable.

By late 1945, as Japan’s surrender became official and repatriation planning began, the psychological transformation of the Japanese women PSWs was evident in their private writings and conversations.

Many expressed anxiety about returning to a Japan where disposable sanitary napkins didn’t exist.

where they would return to washing and reusing cloth, where menration would again become a source of constant worry and discomfort.

Lieutenant Yamamoto wrote extensively about her concerns.

I will return to a destroyed Japan where we will struggle to obtain food and basic necessities.

The idea of returning to cloth pads seems unbearable after experiencing these American napkins.

But more troubling is the question these products have raised.

If America can mass-roduce solutions for women’s monthly discomfort, what else might be possible? What other aspects of life that we accept as unavoidable hardship might actually be solvable through industrial innovation and social openness? I fear returning to Japan, not because it is destroyed, but because I now know life could be easier than we were taught to accept.

The repatriation began in early 1946.

Japanese women ps were allowed to take with them their personal belongings, including remaining supplies of sanitary napkins.

Many hoarded their final boxes like treasures, knowing they represented months of comfort before reverting to traditional methods.

American authorities, recognizing the impact of this simple product, included sanitary napkins in Red Cross packages sent to Japan during the occupation.

The quantities were limited, but the symbolic importance was significant.

Japanese women who had never seen such products now learned of their existence, creating demand that would eventually transform Japanese manufacturing.

The return to Japan brought the stark contrast into sharp relief.

The Japanese women who had experienced American sanitary napkins found readjustment to cloth pads difficult physically and psychologically.

But more significantly, they became informal advocates for industrial solutions to women’s needs.

Captain Tanaka, returning to her nursing career in occupied Tokyo, began teaching younger nurses about American sanitary products she had encountered.

Her lessons went beyond the products themselves to discuss the philosophy behind them, that women’s comfort and health deserved industrial attention, that menstruation needn’t be managed in silence and shame, that practical solutions were possible if society chose to create them.

Within 5 years, Japanese companies would begin manufacturing disposable sanitary napkins, learning from American examples.

The products were initially expensive and considered luxury items, but gradually became more affordable and widespread.

By the 1960s, most urban Japanese women used disposable napkins, and by the 1970s, they were standard across Japan.

The transformation wasn’t simply about adopting American products.

It represented a broader shift in how Japanese society thought about women’s needs, health, and comfort.

The post-war generation of Japanese women, influenced partly by those who had witnessed American practices during the occupation, began expecting and demanding accommodations that their mothers had endured without complaint.

The market research reports from the 1950s, Japan documented this change.

Surveys showed that younger Japanese women specifically wanted products like American women use and were willing to pay premium prices for them.

Advertising for early Japanese sanitary napkins explicitly referenced American brands and manufacturing methods.

The cultural message was clear.

Modernity meant treating women’s health needs as seriously as Americans did.

In 1953, Lieutenant Yamamoto, now working at a Tokyo hospital, wrote a reflection piece for a nursing journal about her P experience.

The article focused on the sanitary napkin revelation and its broader implications.

During my captivity, I received a monthly box of disposable sanitary napkins.

This small package revealed more about American society than any amount of propaganda could have.

It demonstrated that American industry considered women’s comfort worthy of sophisticated engineering and mass production.

It showed that American culture treated menstruation as a practical problem to solve rather than a shameful secret to endure.

It proved that when a society values women’s health and comfort, industrial solutions follow naturally, the sanitary napkin was not simply a product.

It was evidence of a civilization that had decided women’s well-being mattered enough to justify significant industrial investment.

We lost the war to American weapons, but we also lost to American values about women’s worth.

The sanitary napkins taught me this lesson more effectively than any political speech.

The article resonated with Japanese women who had begun demanding better products and more open discussion of women’s health issues.

It became one small part of a broader cultural shift in post-war Japan toward greater acknowledgement of women’s needs and rights.

By the 1960s, American sanitary napkin brands, including Cotex, had entered the Japanese market, competing with domestic manufacturers who had learned from American examples.

The products were widely available, affordable for middleclass women, and advertised openly in magazines and on television.

Japanese school girls received education about menstruation and sanitary products similar to what American girls had received for decades.

The transformation was so complete that by the 1980s most young Japanese women had no memory of cloth pads and couldn’t imagine managing menstruation without disposable products.

The old ways had been almost entirely replaced within a single generation.

The story of Japanese women psing American sanitary napkins might seem like a footnote to World War II’s grand narrative of battles and political transformations.

But for the women who experienced it, the revelation was profound and life-changing.

It wasn’t simply about a useful product, though it certainly was that.

It was about discovering that aspects of life they had been taught to accept as unchangeable could actually be transformed through industrial innovation and cultural willingness to address women’s needs openly.

The statistical summary tells part of the story.

By 1945, America was producing approximately 3.5 billion sanitary napkins annually.

Japan produced zero.

American women, including those in military service and even enemy prisoners, received regular supplies of sophisticated menstrual products.

Japanese women used cloth and accepted discomfort as natural.

The disparity wasn’t simply about industrial capacity, though that was part of it.

It was about societal priorities and values regarding women’s health and comfort.

For the 347 Japanese women processed through Guam in August 1945, the small rectangular package they received that first day became a symbol of everything they hadn’t understood about American society.

It represented industrial sophistication applied to everyday problems.

It demonstrated cultural openness about topics Japanese society shrouded in shame.

It proved that women’s comfort could be a legitimate priority for serious engineering and manufacturing resources.

Most importantly, it revealed that some hardships Japanese women had been taught to accept as inevitable were actually solvable if society chose to solve them.

The sanitary napkin wasn’t just a product.

It was a possibility, a suggestion that life for women could be easier, more comfortable, more dignified than tradition had allowed them to imagine.

The German PS who discovered American abundance through Coca-Cola and ice cream experienced one kind of psychological transformation.

The Japanese women who discovered it through sanitary napkins experienced something more intimate and perhaps more profound.

They learned that even the most private aspects of women’s lives, the functions and discomforts that all societies had considered natural and unchangeable, could be addressed through industrial innovation if culture permitted it.

In the end, the disposable sanitary napkin represented more than American industrial might.

It represented a fundamentally different approach to women’s place in society.

America hadn’t just outproduced Japan in tanks and planes.

It had created a civilization where women’s monthly discomfort was considered worthy of scientific research, engineering investment, and mass production solutions.

This was a kind of victory that military force alone could never achieve.

A demonstration of values and priorities that transformed hearts and minds more effectively than any propaganda campaign.

The Japanese women ps returned home carrying not just memories of sanitary napkins, but a revolutionary idea that women’s comfort and health could be legitimate priorities for industrial society, that biological functions needn’t be shrouded in shame, that innovation and openness could transform even the most private aspects of women’s lives.

They became unwitting agents of cultural transformation, carrying seeds of change that would eventually blossom into a new Japan where women’s needs received the attention and accommodation they deserved.

The small rectangular package given to Lieutenant Yamamoto on that August day in 1945 contained more than cellucotton and gores.

It contained a future where Japanese women, like their American counterparts, would expect and receive industrial solutions to the challenges of being female.

The transformation took decades, but it began with that moment of shock discovery when 347 Japanese women learned that sanitary napkins existed and that even enemies received them free, revealing an America more powerful and transformative than they had ever imagined.