The movie follows the real-life story of Louis Zamperini as told in a 2010 book by Laura Hillenbrand. The book has not been translated into Japanese, but online trailers have provoked outrage. Zamperini, played by Jack O’Connell, survived in a raft for 47 days with two other crewmen after their B-24 bomber crashed into the Pacific Ocean, only to be captured by the Japanese and sent to a prisoner-of-war camp. Especially provocative is a passage in the book that accuses the Japanese of engaging in cannibalism of POWs. It is not clear how much of that will be in the movie, but in Japan that is too much for some.
I read the book twice but I haven't come across a relevant passage on cannibalism of POWs. Some Japanese soldiers in Papua New Guinea resorted to cannibalism during the war because they were on the brink of death from starvation. The 2010 book was written like a novel rather than a history book and there may be some factual inaccuracies to produce dramatic effects. Laura Hillenbrand previously wrote "Seabiscuit: An American Legend" (2001), a nonfiction account of the career of the great racehorse Seabiscuit. The author is not a military historian, which may be why she mixed up what happened in Papua New Guinea with the abuse of the POWs.
The Persians under Cambyses while they were marching through the Egyptian desert ran out of food and had to cannibalize each other. When Cambyses heard about it he was unnerved, and they immediately turned around and marched back to where they came from. Herodotus tells us.
The Donner Party were a well known cannibalistic group in the 1840's.
Anytime you get into a food crunch and there is not any food, you need to think seriously about cannibalism.
You can play the game of waiting for someone to die, and eat them.
Or you can take the initiative like the soldiers of Cambyses did and also like the Donner Party did.
The point is that if you all die it won't do anybody any good.
In the meantime you can always eat bugs. Bugs taste better cooked -- like French fries.
Worms too -- they also taste better cooked. Try a little taste first, like when you were eating buggers as a kid. Then eat more. Finally you will get used to bugs and worms.