The Sea and Poison (1986) IMDb
Seen in 2016.
Intentionally fatal medical experiments on American POWs in WW2 Japan.
Drama. The POWs don’t even come up in conversation until some 56 minutes into the film, which is a good choice. Up until that point it’s a skilled and interesting depiction of the hierarchical culture of a hospital under a totalitarian 1940s regime influenced by German traditions and humorously visited by a saintly German nurse whom all the Japanese despise. The addition of the war crimes adds depth and that great rarity of Japanese culture: A sincere acknowledgement of the horrors of WW2.
References here: “Don't mention the war!”.