The 47th Samurai by Stephen Hunter

I really enjoy this series and the narrator is excellent. Wacky premiss but somehow this was really entertaining. PW Bob Lee Swagger and Philip Yano are bound together by a single moment at Iwo Jima, 1945, when their fathers, two brave fighters on opposite sides, met in the bloody and chaotic battle for the island. Only Earl Swagger survived. More than 60 years later, Yano comes to America to honor the legacy of his heroic father by recovering the sword he used in the battle. His search has led him to Crazy Horse, Idaho, where Bob Lee, ex-marine and Vietnam veteran, has settled into a restless retirement and immediately pledges himself to Yano's quest.