Former US Marine returns a flag he took from a fallen Japanese soldier during WWII

A US Marine who served in the Pacific during World War II has travelled to a remote village in Japan to return a flag he took from the body of a fallen Japanese soldier 73 years ago.

Marvin Strombo, who had taken the calligraphy-covered Japanese flag, returned it on Tuesday to the family of Sadao Yasue.

They had never gotten his body or - until that moment - anything else of his. Yasue's sister Sayoko Furuta, 93, sitting in her wheelchair, covered her face with both hands and wept silently as her brother Tatsuya Yasue placed the flag on her lap.

Mr Strombo reached out and gently rubbed her shoulder.

"I was so happy that I returned the flag," Mr Strombo said.

"I can see how much the flag meant to her.  That almost made me cry ... It meant everything in the world to her."

The flag's white background is filled with signatures of 180 friends and neighbours in this tea-growing mountain village of Higashishirakawa, wishing Yasue's safe return.

The signatures helped Mr Strombo find its rightful owners. "Good luck forever at the battlefield," a message on it reads.

The return of the flag brings closure, the 89-year-old farmer and younger brother of Sadao Yasue told The Associated Press at his 400-year-old house on Monday.

"It's like the war has finally ended and my brother can come out of limbo." Tatsuya Yasue last saw his older brother alive the day before he left for the South Pacific in 1943.

He and two siblings had a small send-off picnic for the oldest brother outside his military unit over sushi and Japanese sweet mochi.

At the end of the meeting, his brother whispered to Tatsuya, asking him to take good care of their parents, as he would be sent to the Pacific islands, harsh battlegrounds where chances of survival were low.

A year later, Japanese authorities sent the family a wooden box with a few stones at the bottom - a substitute for his body.

They knew no details of Sadeo's death until months after the war ended, when they were told he died somewhere in the Mariana Islands presumably on July 18, 1944, the day Saipan fell, at age 25.

"That's all we were told about my brother. We never knew exactly when, where or how he died," he said So Mr Strombo was able to give Yasue's family not just a flag, but also some answers.

He said he found Sadao Yasue's body on the outskirts of Garapan, a village in Saipan, when he got lost and ended up near the Japanese frontline.

He told Yasue's siblings their brother likely died of a concussion from a mortar round.

He told them that Sadao was lying on the ground on his left side, looking peacefully as if he was sleeping and without severe wounds.

The remains of nearly half of the 2.4 million Japanese war dead overseas have yet to be found.

It's a pressing issue as the bereaved families reach old age and memories fade.

Allied troops frequently took the flags from the bodies of their enemies as souvenirs, as Japanese flags were quite popular and fetched good prices when auctioned, Strombo said.

But to the Japanese bereaved families, they have a much deeper meaning, especially those, like Yasue, who never learned how their loved ones died and never received remains.

Japanese government has requested auction sites to stop trading wartime signed flags.

Mr Strombo said Tuesday that he originally wanted the flag as a souvenir from the war, but he felt guilty taking it, so he never sold it and vowed to one day return it.

He had the flag hung in a glass-fronted gun cabinet in his home in Montana for years, a topic of conversation for visitors. He was in the battles of Saipan, Tarawa and Tinian, which chipped away at Japan's control of islands in the Pacific and paved the way for US victory.

In 2012, he was connected to the Obon Society, an Oregon-based nonprofit that helps US veterans and their descendants return Japanese flags to the families of fallen soldiers.

The group's research traced it to the village of 2,300 people in central Japan by analysing family names.

Tuesday's handover meant a closure for Mr Strombo too.

"It means so much to me and the family to get the flag back and move on," he said.