Here is the basic translation of the above plaque...

Unknown Scout Soldier -- This statue is a memorial of a true story of a fierce battle in World War II, which happened on an island in the South Pacific Ocean somewhere. An American soldier was seriously wounded, and he was lying where he had fallen. The sound of gunfire stopped, and the surroundings quieted down. He heard someone's footsteps approaching him. A Japanese soldier who had a gun with a bayonet was standing over him when he opened his eyes. He thought that he was going to be killed by the Japanese soldier, and he fainted. After a while, he woke up. He found a white slip of paper on the sand by his side, and he put it in his pocket. He was carried on a stretcher to the field operations aid station soon after that. When he was put on the operating table, he remembered the slip of paper in his pocket, and gave it to the doctor. It was a message from the Japanese soldier, and was as follows: "When I was about to kill you, you made the three fingered Scout salute. I am a Scout. A Scout is a brother. Therefore, I could not kill any person who lost the fighting spirit. I tended to your wound. Good luck!" After the war the American soldier and his father visited the Boy Scout headquarters in the United States, and told this story. They donated money for the Boy Scouts to put up a monument to the Scouting Spirit. In 1952, Mr. Finnel came to inspect the Boy Scout movement of Japan from the headquarters in the United States and passed on this true story as a fine anecdote from during the war. The American soldier's name is not known. The Japanese soldier was killed. This monument is to the Unknown Scout Soldier. This is an example of the Scout Spirit of Japan.