Inside the walls of the Zen Buddhist Kazo-ji temple in the port of Otomo, in Iwate prefecture, six khaki army tents are pitched beside a stone garden. In the car park, soldiers gathered round a field mess preparing a midday meal for those made homeless by the tsunami in March that devastated Otomo.

Out over the bay two helicopters slowly skimmed the waves. With some 12,000 people still missing, a drive was under way last month to locate more bodies. A contingent of 25,000 soldiers, 90 helicopters and 50 naval units, assisted by about 100 divers, took part in the operation. Some bodies remain buried in the wreckage; others were swept out to sea.

Several weeks after the earthquake and tsunami, Japan's self-defence forces are still hard at work in Otomo and in most of the other towns in the disaster zone. SDF convoys sped down the roads, flying banners marked "emergency rescue". Military bulldozers were busy clearing wreckage.

The presence of troops gives the devastated towns a war-time atmosphere. But local people are generally pleased to see them. "Without them, I don't know what would have become of us," says one Otomo resident.

Many Japanese have misgivings about these forces. With the difficult legacy of militarism, the pacifist stance written into the constitution and the ambiguity surrounding the unnamed army, soldiers feel obliged to keep a low profile. Their work since the tsunami has undoubtedly been their most effective public relations move.

It's the first time since 1945 that such a large number of military personnel have been deployed on Japanese territory. The SDF, which is also involved in emergency work at the Fukushima power station, may gain the legitimacy it has previously lacked in the public's eyes.

Under the constitution of 1947 Japan renounced the threat or use of force, but soon yielded to American pressure at the start of the cold war and the conflict in Korea, setting up a reserve force, followed in 1954 by self-defence forces. For years the Japanese were uncertain about the mission assigned to the SDF – defending the country along with emergency rescue work in the event of a national disaster.

In the original mission statement the force was required simply to assist civilian authorities, though due to the scale of the March disaster the SDF has taken on a much larger role. Immediately after the tsunami, the SDF was the only organisation equipped to cope with conditions, if only because its communications resources enabled it to continue operations.

The SDF was mobilised on the evening of 11 March for emergency transport, but soon became the main body managing the crisis. Almost half the force of 230,000 has been mobilised under a single command structure controlling land, sea and air forces.

"After the emergency rescue operations we are now clearing debris and helping disaster victims resume normal life and dispensing medical care," says Lieutenant Kimura of the fifth infantry regiment, ninth division. Just under 600 men and women from the regiment have been deployed in Rikuzentakata, one of the cities hardest hit.

"The personnel are trained to deal with disasters," Kimura adds. The soldiers, most of whom are young, provide material assistance, but they often listen to victims too. The hardest task, said one soldier, is searching for bodies. "We move forward in a line with long wooden poles, stirring the debris," he said. "When a corpse is found, the search stops and the police take over."

Soldiers only start using heavy machinery to retrieve a body once the family's approval has been obtained. "This procedure slows down our work," the soldier adds, "but it's right we should respect the suffering of disaster victims."

This article originally appeared in Le Monde