The Takeyamas have tried to move on and forget the enormous waves that swept away relatives, their home and the lives they once had.

But the couple, both in their seventies, still spend countless nights staring at the ceiling of their tiny makeshift house, built after Japan's quake-tsunami disaster three years ago, thinking about better times.

Before a towering wall of water turned the northeast coast into a wasteland of shattered communities, Iwako Takeyama and her husband Toichi lived in a sturdy home in Ogatsu town, with a daughter and other family nearby.

"People say it's good to live close to a daughter and her family so they can bring you a cup of soup without getting it cold," said 73-year-old Iwako.

"But the tsunami flushed away both of our houses, ours and hers."

Like thousands of other survivors, the elderly couple lost relatives -- one sister, two brothers and a nephew -- after a huge undersea earthquake shook Japan at 2:46 pm on Friday, March 11, 2011.

Its 9.0 magnitude force unleashed a towering tsunami that travelled at the speed of a jet plane to the coast.

Within minutes, communities were turned to matchwood, and whole families had drowned.

Officially, more than 15,800 people are known to have died in the disaster. Another 2,636 are listed as missing.

The body of Toichi's sister was recovered about 30 kilometres (19 miles) offshore.

"We spent days looking for the bodies after the tsunami," Iwako said as her eyes filled with tears.

"We are finally feeling OK now."

- Hard lives, fading hope -

But while the nightmare fades for many in other parts of Japan, tens of thousands of refugees are still struggling to cope as the country gets set to mark the third anniversary of the disaster on Tuesday.

The government has pledged billions of dollars in reconstruction funds but the Takeyamas and many others are still struggling to make do in cramped temporary housing.

The stress of living in a 30-square-metre (320-square-feet) space has taken a heavy toll on their mental and physical health, they said. Toichi has been hospitalised twice since the disaster.

"You can tell exactly what your neighbour is doing next door, taking a bath or using the toilet," Toichi said. "We cannot even have a quarrel in private."

They hope to move to newly built community housing, but that could still be several years away.

Japan has so far built only 3.5 percent of the new housing promised to refugees in heavily affected Iwate and Miyagi prefectures.

The local government of Fukushima prefecture, where a tsunami-crippled nuclear plant is located, does not even have a number for how many new houses it needs to house evacuees forced to flee the worst atomic crisis in a generation.

As a result of the tsunami and Fukushima crisis, among almost 270,000 evacuees as of last month, 100,000 are in temporary housing. It remains unclear how many more years it will take to build all the needed post-disaster housing.

- Struggling to make ends meet -

In the town of Onagawa, many refugees have tried to keep busy by making Japanese-style sandals with donated T-shirts, selling them for 1,500 yen ($15) to make ends meet -- and trying to forget their grim reality.

"I wonder if I will be still alive when we move out of this temporary house," said Kazuko Kimura, 86. "I want to die in a new house with no worries about the future."

Sawako Kishi, 76, spends many sleepless nights haunted by the uncertainty.

The devout Buddhist has an altar in the small bedroom of her family's tiny makeshift home, with their belongings and futon taking up most of the living space. They hold out hope for a permanent home, but progress has been slow in the rugged mountain town.

"They first have to cut into the mountainside and build a new road tunnel. Building our house will come after that," she said.

Among the myriad challenges, many lots on higher ground are the property of hundreds of small landowners who are loathe to give up their real estate.

"This is the biggest challenge and we should look at changing the law" to make it easier to build public housing on those plots, said Kosuke Motani, chief economist at Japan Research Institute.

With the focus on rebuilding, the government has barely scratched the surface in dealing with refugees' mental health, said Tsuyoshi Akiyama, a neuropsychiatry doctor and clinical professor at Tokyo University.

"Whatever choices disaster victims make, they face some sort of mental stress in one way or another," he said.