Kensuke's kingdom (1999)

Michael's parents buy a yacht, and take him off to sail round the world. Washed overboard in a fierce storm, Michael finds himself on the shore of a remote island - and soon discovers he's not alone. Kensuke, a former Japanese soldier, survived the war and the bombing of Hiroshima, but his family perished. As an extraordinary bond forms between the two, Kensuke faces a heart-breaking choice: can he give up the secluded life he's built for himself to help reunite Michael with his parents?