The Japanese Army atrocities during WW2 included cannibalism.

For the 10,000-odd soldiers of the Indian Army who endured extreme torture at the hands of their Japanese captors, cannibalism was the culmination. Evidence suggests the practice was not the result of dwindling supplies, but worse, it was conducted under supervision of Japanese officers.

On Dec. 25, 1942, the US Army obtained the diary of a Japanese commander who documented starvation of his platoon, and noted that meat had been carved from a dead American prisoner: “This is the first time I have ever tasted human flesh—and it was very tasty.”

In 1993, Hidden Horrors: Japanese War Crimes In World War II by Toshiyuki Tanaka said, "thousands of Australian, British, Pakistani and Indian POWs were massacred, and some cannibalized". Tanaka indicated that he had collected at least 100 documented cases of Japanese cannibalism involving Australian and Indian soldiers. This refuted the contention that the Japanese resorted to cannibalism only when their food supplies were exhausted. “Tanaka said this was done under the supervision of senior officers"