Choho Zukeran was a schoolboy, mobilised to dig beachfront trenches, when US soldiers landed on his native Okinawa, sparking one of the bloodiest battles of the second world war. Over the next few weeks, some 200,000 Japanese and Americans would die, including more than a quarter of Okinawa's civilian population. Most died in the invasion, others killed themselves - on the orders of the army that was supposed to be protecting them.

"The army had given us two grenades each. They told us to hurl the first one at the enemy and to use the second one to kill ourselves," Mr Zukeran told the Guardian from his home in Okinawa, a subtropical island 1,000 miles south-west of Tokyo. Whole families and communities committed suicide together.

Yet if the government in Tokyo gets its way, Japanese children may never learn how hundreds of Okinawa residents, under direct or indirect pressure from the military, took their own lives.

This year the education ministry ordered publishers of seven high-school textbooks to be introduced next April to remove references to the forced suicides. The ministry said "it was not clear there were military orders [to commit suicide]" and that "recent studies suggest there were no such orders".

The demand is part of a growing movement to sanitise - or simply ignore - the darkest episodes in modern Japanese history, which have gathered pace under one of the most conservative governments of recent decades, led by the hawkish prime minister, Shinzo Abe.

A long simmering row over the 1937 massacre of tens of thousands of Chinese civilians in Nanking by Japanese forces has been reignited by renewed efforts to play down the carnage. Last month about 130 Japanese MPs denounced the massacre as a Chinese fabrication and claimed the death toll was nearer 20,000. Several films marking the 70th anniversary are due for release this year, including one by the rightwing director Satoru Mizushima which describes the episode as a myth.

Other attempts by the Japanese right to rectify Japan's "masochistic" view of its own history have set it on a diplomatic collision course with its closest ally, the United States.

Last month a congressional committee passed a resolution calling on Japan to acknowledge and apologise for forcing an estimated 200,000 mainly Chinese and Korean women to work in frontline brothels - the so-called "comfort women". Mr Abe caused uproar when he denied the women had been coerced, and was forced to reiterate his support for an informal 1993 apology issued by the then parliament speaker.

Hiromichi Moteki, secretary-general of the rightwing Society for the Dissemination of Historical Fact, denies Japan's current obsession with reinterpreting the past is politically motivated. "We are now able to look again at our history now that the facts have come to light," he said. "We have been listening to the left's fabrications for years, but now we have the truth in front of us."

The drive extends to the rehabilitation of wartime politicians closely associated with militarism. Yuko Tojo, whose grandfather, Hideki, was prime minister during the war and was hanged as a war criminal in 1948, says clearing her grandfather's name is part of a mission to restore "pride and confidence".

"There is no need to apologise to anyone - our ancestors are not guilty of the crimes of which they have been accused," said Ms Tojo, 68, who is running as an independent in elections. "If my grandfather is to be blamed for anything, it is not that he started the war but that we lost it."

Japan's defeat probably saved Mr Zukeran's life. After a week in a beach cave in June 1945, hunger triumphed over fear and his family surrendered. "We soon realised we had been lied to. The Americans were not going to kill us.

"Lots of my school friends were told to commit suicide by Japanese soldiers. At school we had been brainwashed ... [that] to surrender to [US troops] would be to disgrace the emperor," said the 75-year-old retired teacher and local councillor.

The attempt to airbrush the suicides caused outrage in Okinawa and prompted half its towns and villages to demand the references stay.

"It is an undeniable fact that mass suicides could not have occurred without the involvement of the Japanese army," the Okinawa city assembly said.

More than six decades on, Mr Zukeran is appalled at what Japan's modern-day leaders are trying to do.

"Many of my friends died because they were told to. The army never once tried to protect us. They told people to die and stole food intended for women and children. That is how war robs people of their humanity."

In the weeks after the invasion, Mr Zukeran's family walked from village to village to escape the Americans who, they had been told, would rape and kill them amid a "typhoon of steel".

Eyewitnesses claim entire families committed suicide together on the orders of fanatical Japanese soldiers rather than allow them to surrender and betray sensitive information about troop movements. Some 700 committed mass suicide in the Kerama islets off Okinawa.

· This article was amended on Friday July 6 2007. When we said in the first paragraph that "some died in the invasion", we should have said "most". In the third paragraph we said, "Yet if the government in Tokyo gets its way, Japanese children may never learn how thousands of Okinawa residents ... took their own lives." This should have read "hundreds" not "thousands". The article has been corrected.