The two old men apparently declared they were soldiers, and the story they told when they emerged from the dense jungle of a Philippine island was yesterday the talk of the nation they claimed to have fought for.
According to reports, the Japanese men, who are both in their 80s, said they had been hiding on the island of Mindanao, which is 600 miles from Manila, since before the end of the second world war.
The Kyodo news agency identified them as Yoshio Yamakawa, 87, and Tsuzuki Nakauchi, 85, and said they were former members of a division whose ranks were devastated in fierce battles with US forces towards the end of the war.
The soldiers had remained in the jungle and mountains since then, possibly unaware that the war had ended 60 years ago, and afraid that they would be court-martialled for desertion if they showed their faces again.
The revelation provoked an immediate response in Tokyo, with the prime minister, Junichiro Koizumi, dispatching a team of diplomats to try to verify the stories.
Mr Koizumi told reporters that if the two were found to be Japanese soldiers, everything would be done to repatriate them if that was what they wanted.
"If they are alive, we'd like to fulfill their wishes," he said. "If this turns out to be true it will be quite a surprise. They have done really well to stay alive this long."
If yesterday's reports are true, it would be the first time a Japanese soldier has been found alive for more than 30 years.
In 1974, Hiroo Onoda, a Japanese army intelligence officer, caused a sensation when he was persuaded to come out of hiding by a former comrade on the Philippine island of Lubang.
Mr Onoda, now 83, wept uncontrollably as he agreed to lay down his rifle, unaware that Japanese forces had surrendered 29 years earlier. He returned to Japan the same year, but unable to adapt to life in his home country, emigrated to Brazil in 1975.
In 1972, Shoichi Yokoi was found on the island of Guam and returned to Japan, where he died in 1997. Like Mr Onoda, he had no idea that the war had ended.
The drama began on Thursday when a Japanese mediator for a veteran's group who was on Mindanao searching for the remains of former soldiers told the Japanese embassy in Manila that he had been contacted by the men and would be able to deliver them to the island's capital, General Santos, yesterday afternoon.
But hopes of confirming their identities were dashed when they men failed to materialise, possibly scared off by the media attention.
"There has been nothing concrete at all today; nothing has happened," an embassy spokesman, Shuhei Ogawa, told the Guardian from the hotel where the Japanese delegation was waiting. With expectation mounting at home, Japanese officials on the ground said they were not ready to give up. The embassy delegation plans to stay at least until today.
"We don't know beyond that," Mr Ogawa said. "It depends on what happens. We believe someone from the social welfare ministry is due to leave Japan tomorrow but we don't know when they will get to General Santos City."
A close associate of a veterans' organisation in Japan that knows the mediator told the Guardian he was confident that the men exist.
"I understand that they produced some form of identification and wrote their names in Japanese," said Kazuhiko Terashima, whose father, Yoshihiko, is president of a group that searches for the remains of Japanese soldiers. "Then they said they wanted to return to Japan, so the mediator contacted the Japanese embassy."
Mr Terashima said he believed the men, who were dressed in civilian clothes, had fled back into the mountains because they were unsettled by the presence of so many Japanese reporters in the area.
Japan invaded the Philippines in 1941, hours after the attack on the US at Pearl Harbor, in Hawaii. It conducted a brutal occupation that killed an estimated one million Filipinos.
But the historical background barely merited a mention in media coverage in Japan, where speculation mounted that the octogenarians, if found to be genuine, would return home more than 60 years after they left as young men to fight for the emperor.
"If they come, we will ask them if they can speak Japanese and if they want to return to Japan," said Shinichi Ogawa, the Japanese consul for Davao, the main city on Mindanao.
Negotiators and former soldiers regularly travel to the Philippines to investigate reports of Japanese military stragglers living in mountain jungles, apparently unaware that the war had ended.
An estimated three million Japanese troops were stationed overseas when the wartime emperor, Hirohito, surrendered in August 1945. Unaware of their country's capitulation, some went into hiding, holding on to their weapons and ammunition for years and evading patrols of allied troops.
"We always have rumours about war veterans turning up alive in remote parts of the Philippines," Mr Ogawa said. "But this time the story seemed more credible. We had someone who promised us concrete information, a meeting on a certain day. So we took it more seriously."
