Tokyo The Chinese called Waichi Okumura a devil. He says he was no more than an ant. He bayoneted a civilian to death as part of his training in the closing days of the second world war, then stayed on in Shanxi province to fight the communists and try to build a new Japanese empire. More than 60 years later, he's one of the few still alive to recall those days. He so impressed Kaoru Ikeya with the anger that burns inside him still that the documentary-maker knew he had a compelling tale to tell. 'He is both angry and sad,' says Ikeya. 'He was sad to go back to the places where so many of his friends died and to meet the people whose lives they affected. He is angry because he believes the Japanese government is making up history. He is suing the government, but it's not about money. He just wants the lies to end. He feels dishonoured.' The Ants: The Day I Became a Devil won the humanitarian award for outstanding documentary at this year's Hong Kong International Film Festival and has been shown at cinemas in Tokyo, Nagoya and Osaka for the past month. Known as Ari no Heitai in Japanese, it's scheduled to open in other cities in the next few weeks, including Okinawa and Sapporo. About 10,000 people have seen the movie, and it has taken US$132,000 at the box office. Okumura, now a frail man of 80, attended a special day-long programme of screenings and discussions in Tokyo on August 15, the 61st anniversary of Japan's surrender at the end of the second world war, at which he told the audience that his war was not over, Ikeya says. 'He said he doesn't want to leave an incorrect representation of history behind, so he will continue his fight. And he said war makes good people really evil.' Okumura's story began in February 1945, when he arrived as a conscript for the Imperial Japanese Army in China. His training included the murder of a Chinese man - Okumura says he closed his eyes as he repeatedly drove the bayonet into the man's body and he can no longer remember his face - but the war ended six months later. Anticipating repatriation to Japan, he was instead ordered to remain in Shanxi province with about 2,600 other soldiers of the 1st Imperial Army, under the command of General Raishiro Sumida, a wanted Class-A war criminal. They were told to fight alongside Kuomintang troops - whom they'd been fighting against months earlier - against Mao Zedong's communist forces. As a lowly foot soldier, Okumura was unaware of the details of any agreement, but documents in China detail a pact under which the Kuomintang's Yan Xishan would protect Sumida and, in return, imperial Japan would have a new homeland once the communists were defeated. Okumura was injured during the fighting - he still has shrapnel in his body - before being captured by the communist forces. Nine years after the end of the war, he was able to return to Japan. He spent the following decades struggling to make a living, but at reunions with fellow veterans he began to ask why they had been forced to stay behind. In 1988, a group filed a petition with the government demanding to know why they had been ordered to continue the war, in contravention of the Potsdam Declaration. In 2001, they sued the government in an effort to win an admission that a military order had been issued that caused their fate. A series of court rulings went against them, judges deciding that they had been volunteers and that the government was not obliged to pay them a military pension. Last year, the Supreme Court reached the same conclusion, despite holding no public hearings. 'Emotionally, it was a very difficult movie to make,' says Ikeya, whose previous works have included documentaries about China and the US, as well as the critically acclaimed Daughter from Yan'an, which documents the chaos and inhumanity that fuelled the Cultural Revolution in China. 'Okumura had to return to places where he had fought, where he had killed people, and speak with people who lived through those times,' he says. 'It was hard on me and the rest of the crew during the shooting as you cannot help but ask yourself what you would have done in that situation. It became our issue as well. 'He went looking for witnesses to the time when he bayoneted the Chinese civilian to death, but couldn't find anyone who remembered it.' In the film, after his harrowing return to China, where he finds documents supporting his contention that the government ordered him and his colleagues to continue the fight, Okumura goes to the Yasukuni Shrine, which honours the 2.5 million Japanese who have died in battle and is a cornerstone of Japanese nationalism. There, he meets young people celebrating a festival and is astonished at their lack of knowledge about the past. But he refuses to go into Yasukuni, which also enshrines 14 Class-A war criminals, on the anniversary of the end of the war. 'The people who led Japan into the war are enshrined there,' says Ikeya. '[Okamura] and his friends fought in China and many of them died there. It was the leaders revered at Yasukuni who are to blame for that.' Ikeya says he was 'very honoured' to receive an award in Hong Kong and is delighted that the movie is likely to be screened in the US and Canada. And he's planning his next movie: the highest court in Japan may have dismissed Okumura's petition, but the old soldier is refusing to let the matter drop. Ikeya intends to keep his camera rolling to record the next stage in his life-long fight.