David McNeillreports from Tokyo on the reaction to Clint Eastwood's second film about the battle for Iwo Jima, told from the Japanese perspective and starring local actors.

A familiar lanky figure was seen strolling through the corridors of Japan's parliament buildings. Clint Eastwood was in town - his first trip to Tokyo in four decades - to research Letters from Iwo Jima, the second of his two-part, second World War epic which began with Flags of Our Fathers.

The iconic star had decided midway through making Flags of Our Fathers that he was "telling only half the story", and decided to make a second movie told entirely from the Japanese perspective, with subtitles and local actors. "These men [ Japanese soldiers] gave their lives for what they thought was to defend their country," he later said. "They deserve respect just as the American forces do."

Eastwood's quest for authenticity led him to the office of lawmaker Yoshitaka Shindo, grandson of Tadamichi Kuribayashi, the general who defended the island in 1945. "He wanted to know what kind of man my grandfather was," says councillor Shindo. "He told me he didn't want to make a movie simply about war, but about families and the human heart."

A speck of volcanic rock in the Pacific Ocean about 1,126km south of Tokyo, Iwo Jima was the site of one of warfare's most brutal battles. The 20.7sq km island was blasted almost flat, becoming what one veteran called a "sulphurous, crater-filled hellhole" in six weeks of intense fighting in February and March 1945.

When the fighting stopped, nearly 7,000 Allies were dead and just 1,080 of the 21,800 Japanese troops defending the island had been taken alive.

The black sands of Iwo Jima passed into military legend, immortalised in Joe Rosenthal's photo showing a group of US marines raising the Stars and Stripes on Mount Suribachi on February 23rd, 1945. The battle remains, after 60 years of blood-soaked history in Korea, Vietnam and Iraq, the US marines' deadliest. Nearly one-third of all marines killed in the second World War died on the island.

The Americans, at least, had their glory. Japanese veterans were treated like pariahs, blamed for the madness that had consumed their country and stigmatised by rumours of atrocities. "Nobody wanted to hear our stories," says Satoru Omagari, who was a sub-lieutenant in the imperial navy air force. "We never spoke about what had happened."

Gen Kuribayashi died on Iwo Jima and languished in historical obscurity. National reflection was quickly replaced by the collective amnesia that has gripped Japan since. For most postwar Japanese, knowledge of the battle came from short, arid descriptions in school textbooks. Ken Watanabe, the actor who plays Kuribayashi, had never heard of it.

Eastwood knew he would be battling both this amnesia and the enormous weight of cultural stereotype when he began to research Letters from Iwo Jima. Hollywood's default setting for America as the good guys has ensured the bulk of its product on the Pacific War is populated by a cast of banzai-screaming, identikit "nips" bent on self-destruction. Hordes of these crude caricatures were mowed down by John Wayne's marines in Sands of Iwo Jima (1949), the first attempt to film the battle.

Eastwood worked hard to transform this robotic enemy into flesh and blood, hiring a Japanese-American screenwriter, talking to veterans and selecting Japanese actors with whom the audience would empathise. Baby-faced pop star Kazunari Ninomiya is the innocent baker Saigo, drafted into a doomed defence of the island. Like the US soldiers in Flags of Our Fathers, he and his colleagues are depicted as expendable cogs in a military machine.

The director needed to get the battle right - for one thing, Japan is the world's second-largest market for Hollywood movies. However, he has said his motive was not financial but to change American views of Japan which were shaped by the movies he watched growing up. "One side was good and one side was the villain. Well, we know that war just isn't like that."

Faith of Our Fathers and Letters from Iwo Jima have become one of the year's biggest cultural talking points in a nation still wrestling with its conduct during the second World War. After all, Japanese conservatives such as prime minister Shinzo Abe use very similar language when explaining why they visit the controversial Yasukuni war memorial, which honours 14 Class-A war criminals along with millions of soldiers.

In recent years, Japan under Abe and his predecessor, Junichiro Koizumi has begun a reappraisal of the war era that is slowly chipping away at the architecture of the pacifist state and souring relations with its Asian neighbours. China and Korea accuse them of adding a patina of soft nationalism to Japan's national amnesia. Letters is unlikely to find many fans in those countries.

Abe, whose grandfather Nobusuke Kishi was himself briefly listed as a Class-A war criminal, liked the movie so much he wrote to Eastwood thanking him. Letters, said Abe, would help the families of the Japanese soldiers find "some kind of closure for their loss". The director has tiptoed around Japan's undigested war history, as he has any allusions to the war in Iraq. "I just wanted to make a statement about the humanity on both sides," he said.

Letters from Iwo Jima was the top box-office draw in Japan over the New Year holidays and is already one of the biggest movies of 2007. The world it depicts is foreign to most young Japanes audiences. "I knew nothing about gyokusai, [ literally meaning to "pulverise the jewel" but referring to the Japanese military tradition of an honourable death], says 19-year-old Yu Hirano. "I can't believe that men my age blew themselves up in caves."

Ultimately, however, only the Japanese men who survived the battle - of whom there are fewer than 100 still alive - can tell if Eastwood's attempt to depict the horror of war has succeeded. Omagari, who was captured after two months fighting on Iwo Jima, is contemptuous. "It's bullshit," he says. "The real soldiers had no food or water. The actors in the movie looked too strong and pretty."

He says no movie could ever do justice to his experiences. "You know, on the island we hid among dead bodies and waited for the US soldiers to come along. ... We cut open their bellies and pulled out their guts to make it look more convincing. I lay there for hours with the flies buzzing and the smell of my dead friends. What movie could show that?"

Letters from Iwo Jima will open in cinemas here on Feb 23rd.