I'll Remember April (1999)

A Japanese submarine off the US West Coast April 1942 is forced to dive quickly, leaving one man outside. Americans of Japanese ancestry face hostility and "relocation camps" while Americans of German ancestry don't. 4 preteen boys, one a 4th generation Japanese American, play soldiers in the woods and help "patrol the coast". When they come across the Japanese man unconscious in an abandoned factory, they're in doubt of what to do. Their attitude towards their "POW" changes when he saves one of the boys from drowning.