Anyone familiar with Company "M" of the Battle of Attu and a American-Japanese Corporal Yashida who provided them with a flag to fly?

Just inherited my grampa's letters and scraps and found an unbelievable typewritten poem by a Sgt. G. Kinsman about this story. Want to know what happened ...

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"It won't be long now until I come home, darling."
(Donald B. Greenwood - 'grampa' - in a letter home to his wife in Oct. 1943 - he came home in Sep. 1945)