He is best known for the controversial The Devil's Gluttony [ja] (悪魔の飽食) (1981), which revealed the atrocities committed by Unit 731 of the Imperial Japanese Army during the Sino-Japanese War (1937–1945).

[1][2] The Devil's Gluttony was serialized in the Shimbun Akahata (Japanese Communist Party's newspaper) in 1980,[1] and subsequently published by Kobunsha (光文社), in two volumes in 1981 and 1982.

[3] In the ensuing controversy, half of a photograph was discovered to be a fabrication, and Kobunsha subsequently withdrew the book.

[4] Morimura won the Edogawa Rampo Prize in 1969 for Death in the High-Rise (高層の死角).

[5] His short story "Devil of a Boy" appears translated into English in Ellery Queen's Japanese Golden Dozen: The Detective Story World in Japan anthology, which was edited by Ellery Queen.