Men Behind the Sun (Chinese: 黑太阳731 / 黑太陽731; pinyin: hēi tài yáng 731, literally meaning "Black Sun: 731") is a 1988 Hong Kong film directed by Mou Tun-fei.
The film is a graphic depiction of the war atrocities committed by the Japanese at Unit 731, the secret biological weapons experimentation unit of the Imperial Japanese Army during World War II. The film details the various cruel medical experiments Unit 731 inflicted upon the Chinese and Soviet prisoners towards the end of the war.
This is the first movie to be rated "III" (equivalent to the US rating NC-17) in Hong Kong.
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