Few aid workers could have imagined the scenes that awaited them as they set out for north-east Japan in the immediate aftermath of the tsunami in March.

For days after the waves destroyed vast stretches of the Tohoku region's coast, patients filled the corridors of hospitals deprived of heat and water, and doctors examined thousands of patients, knowing essential drugs had been swept away by the walls of muddy water. And while they waited for supplies, they watched helplessly as elderly patients who had survived the tsunami succumbed to hypothermia.

When aid workers arrived, they were greeted by scenes of devastation that would not look out of place in a war zone. But this tragedy was being played out in one of the world's wealthiest countries, fewer than 200 miles from the neon-lit opulence of its capital, Tokyo.

One of them, a nurse who was part of an emergency medical team dispatched from Tokyo, has written about her experiences in a blog that offers one of the most detailed accounts yet of the tsunami's toll on the tens of thousands who survived. Thanks to an anonymous translator, every word of her online journal is available in English.

The blog has received scant coverage in the mainstream Japanese media. But it has generated thousands of online comments, most of them messages of gratitude from evacuees and fellow aid workers, and others who simply drew strength from her words. The nurse has declined potential book and interview requests, and clung to her anonymity, as has the blogger who translated her journal into English in a single sitting.

Painstakingly tapped into the nurse's mobile phone at the end of exhausting days touring evacuation zones and hospitals, the blog chronicles eight days that begin with trepidation and end with a reluctant return to Tokyo. In between, there are moments of despair and optimism, even humour. And floods of tears.

The blog opens with the nurse preparing for her imminent assignment to Rikuzentakata, a town in Iwate prefecture where 2,000 of the 23,000 residents died and 80% of its 8,000 homes were destroyed.

Before they leave, she and her fellow medical workers are told what they can expect to find, and warned to keep their emotions in check. The team leader tells them:

"The situation over there is beyond your worst imagination. If any of you have signed up with optimistic outlooks or [out of] a spirit of volunteerism, please leave the team now.

"No matter what happens at the site, DO NOT CRY. We are not going there to express our sympathy. We are going there to provide nursing and medical care. If you think YOU want to cry, think about how much the people there want to cry. The tears of a rich medical team from Tokyo will only be bothersome or even insulting to them."

The nurse describes the moment she arrives in a snowbound Rikuzentakata, her nose irritated by a "sharp, burnt odour", the only sound that of military and media helicopters circling a town that, aside from a few gutted buildings, no longer exists.

Her journey on foot to an evacuation site is punctuated by pauses to clasp her hands in prayer as troops pull yet another body from the rubble. She spends the first of many nights sleeping on the floor, "packed like sardines, regardless of gender" in a prefabricated hut located next to a makeshift mortuary.

At the end of that first night, exhausted but unable to sleep, she begins her chronicle, pausing occasionally in a futile attempt to seek comfort in browsing old photos and messages from friends: "I'd held in my tears all day, so I wrapped myself in a bath towel and cried until morning came."

On her walks through ruined neighbourhoods she encounters residents in shock and eager to share their experiences with someone from the outside:

"They tell us that a pitch-black tsunami about 15 metres high went back and forth and swallowed everything whole. There were many people who were washed away while preparing to run or even while running away after the call for evacuation was made.

"We have religious ceremonies several times a year to pay respect to the ocean, and we've always lived feeling grateful . . . for the ocean, and still . . . our guide was shedding tears as we walked.

"I was already on the verge of crying myself, but I promised not to cry no matter what, so I turned my eyes away from reality and watched the clouded sky instead.

"As the wind blows, a sepia-colored photograph and a new year's greeting card with a picture of someone's baby come flying to my feet. And at every step or two, there is a red flag fluttering in the wind. A whole slew of flags – too many to even begin to count. These red flags are standing to mark places where bodies have been found.

"An old lady is standing in front of one of the flags. She might be about the same age as my own grandmother. 'Dear nurse from Tokyo, there was a house here that my husband worked so hard to build after the war. He never got sick once but now he's dead.'

"It was impossible not to cry."

The extraordinary speed with which tens of thousands of troops cleared rubble from the roads through Rikuzentakata and dozens of other communities was a symbolic, yet ultimately cosmetic, sign of recovery. Beneath the ruins, the human tragedy was still unfolding:

"The streets have been fixed, and much heavy machinery has finally come into Rikuzentakata. And as the rubble is cleared, many dead bodies have emerged.

"Beneath the rubble, I heard the ringtone of a cell phone that finally had reception since the system recovered the day before. It was very difficult . . . painful when the body of a pregnant woman came out."

Her moments of self-doubt – she muses on the futility of applying bandages to people suffering deep emotional trauma – are offset by small triumphs: the appearance of the sun after days of snow, the arrival of medical supplies, and a "gourmet" meal of rice balls, bread and Yakult. The unannounced return of lighting to one shelter is greeted by spontaneous applause: "When everyone's effort takes shape in a visible form like this, it makes me feel like I've been pushed forward to work harder than ever before."

The nurse witnesses firsthand the two most painful threads running through Japan's post-tsunami narrative: the large number of elderly victims, and the displacement of tens of thousands of children. Police figures released last week show that more than two-thirds of the 11,000-plus victims identified so far were aged 60 or over – and that 90% of them had drowned. The advanced age of many of those who died has come to be a defining characteristic of the tsunami. Japan has one of the greyest societies on earth; in the Tohoku region, the over-64s make up almost a third of the population.

They also comprise a large proportion of the shelters' inhabitants. In the first week after the tsunami, Japanese media carried a report about troops arriving at a hospital in Futaba, 10km from the Fukushima nuclear power plant, to find 128 elderly patients, some of them comatose, who had apparently been left to fend for themselves. Fourteen later died, including two who did not last the bus journey to an evacuation centre.

No one knows for sure yet how many children have lost both parents, although the official count is already more than 100. They include a four-year-old girl now living with her grandmother, and a teenage brother and sister who were taken in by their dance instructor. In one of her most emotional posts, the nurse writes about her friendship with an "adorable" six-year-old girl named Luna, whose mother's body was pulled from the rubble clutching her daughter's favourite dolls and books.

In another passage, she recounts talking to a young boy who is poring over a mud-spattered comic about Doraemon, a blue cat with magical powers:

"I talked to a boy who had a fever and a loss of appetite. He showed me a Doraemon book covered in mud. I asked him what his favourite was of all of Doraemon's tools. 'I used to like the ozashiki tsuribori (indoor fishing mat), but now my favorite is the taimu furoshiki (wrapping cloth of time). I want to wrap up the whole city with the taimu furoshiki and make it go back to how it was before the earthquake."

By the time the nurse returns to Tohoku in the summer, the medical focus will have shifted from the acute to the chronic phase, as people run the risk of succumbing to illnesses associated with life as evacuees: blood clots, stress-induced ulcers, pneumonia, high blood pressure and depression.

Children will require counselling to overcome the trauma of seeing their homes and, in some cases, relatives and friends swept away. In April , many began a new academic year in schools with too many empty desks.

Health workers are bracing themselves for a dramatic rise in the number of people with mental health problems, particularly among those who face months living in cramped shelters. Long-term care will require efforts as heroic as those that earned Takeshi Kanno, a 31-year-old doctor in Minamisanriku who saved countless lives on the day of tsunami, a place in TIME magazine's 100 most influential people.

"For a lot of people who up until this point have been able to ignore reality and what actually happened, as they get back on their feet they realise that their house is gone, or their children are dead, and they're being forced to confront these facts," said Toru Hosada, a volunteer doctor in Yamada, a port town in Iwate prefecture. "A lot of them are extremely uncertain as to what they can do."

Meanwhile, the anonymous nurse's blog seems to have brought comfort to many readers.

"On behalf of the people of Iwate and the whole Tohoku region I want to express my appreciation for your work. Thank you," says one.

Another, who has family in Rikuzentakata, writes: "There are many people whose homes have been swept away, their relatives swallowed up by the sea or saved. Knowing that you are there makes me feel better about not being there myself. It might make you angry to hear this, but please shed tears for all of those who have died. Thank you so much. It's dangerous underfoot there, so please take care."

As she prepares to return to Tokyo on 23 March, the nurse is no longer troubled by the minor deprivations of life in the field. She "bathes" with baby wipes, stops fretting about her "sticky hair" and cleans her "dirty, makeup-less face" using tissues moistened with oolong tea.

And as for the town she entered with such foreboding just over a week earlier:

"Rikuzentakata has become my second home, and I wish for the restoration of my homeland with all my heart . . .

"The truly hard times are still ahead of us. As news about the disaster begins to disappear from the TV and other media outlets, everyone else will start to forget, and the problems faced in the affected areas will only increase. More people falling ill, more sadness. It is of course a good thing that the rest of us make an effort to be cheerful and strong and return to our usual lives as best we can, but we must never forget about March 11."

Read blog in English jkts-english.blogspot.com or Japanese blog.goo.ne.jp/flower-wing