In a text message sent at 3.21 pm, half an hour after a huge undersea earthquake shook Japan on Friday, March 11, 2011 and unleashed a towering tsunami that travelled with the speed of a jet plane towards the Japanese coast, Yuko said simply: "I want to go home".

"That was the last message from her," he said.

"I feel terrible thinking she is still out there. I want to bring her home as soon as possible," he said.

Weeks later, while scouring the area, bank workers found Yuko's mobile phone and handed it back to Takamatsu.

He dried it off and fired it up to see that she had written a text message he had never received, at almost exactly the time the water was thought to have reached the roof of the bank.

"'Tsunami huge'. That was all she wrote in the very last one," he said.

Within minutes of the tsunami striking, communities were turned to matchwood, and whole families had drowned.When the waves subsided and the water rushed back out to sea, it took homes, cars and the bodies of thousands of the people it had killed.

Officially, more than 15,800 are known to have died in the disaster, Japan's worst peacetime loss of life. Another 2,636 are listed as missing.

No-one thinks they will ever turn up alive, but for the bereaved, it is important to be able to find their bodies and finally lay them to rest.

More than 800 people were lost in the small fishing town of Onagawa alone, of whom more than 250 are still missing, including Takamatsu's wife, Yuko, then 47.

Minutes after the 9.0 magnitude earthquake, Yuko and a dozen of her colleagues at the local bank went up to the rooftop of the building, aware that a tsunami was rushing ashore.

- 'I felt my knees buckling' -

It was from there that she sent her last text message to her husband.

"It was about the time the tsunami went over the dock of Onagawa. I think the water reached the rooftop a few minutes later," Takamatsu said.

"I was not too worried after the quake...