HIGASHI-SHIRAKAWA, Japan —  Seventy-three years ago, a young Marine from Montana, deployed to the Pacific island of Saipan, stumbled across a body. A Japanese soldier, lying on his back, dead. 
Poking out from underneath his jacket was a “good luck flag” — a Japanese flag covered with the signatures and good luck wishes of 180 people from his family and his hometown of Higashi-Shirakawa, deep in the Japanese Alps. “Long-lasting fortune in battle” was written in large letters across the top.
The 20-year-old Marine, Marvin Strombo, who was part of a scout-sniping platoon, reached down and took the flag. For decades, it was displayed in the glass-fronted gun cabinet in his home in Missoula, Mont., becoming a talking point among visitors and a point of pride for the veteran.
But on Tuesday, the 72nd anniversary of Japan’s World War II surrender, Strombo traveled some 5,300 miles from Missoula to this remote village, …