Bodies of Chinese children are piled in a heap. [Photo provided to China Youth Daily]

In another album collected by Zou, a photo shows bodies of Chinese children piled up. The caption claims the children were abandoned by their families despite allegations that the Japanese Army were involved in the mass slaughter of innocent Chinese citizens, including children, just for fun, during World War II.

Another photo shows a smiling Japanese soldier holding the head of a man while behind him stands another soldier, sword in hand.

Zou, who has a degree in visual communication, is interested in history and has been collecting photos from the war. He tried to verify every one in his collection.

He hopes that the evidence he has collected will be known to the world and make unbearable memories raise an alarm to later generations.

"When I got lost in Japan, local people always helped me warmly," Zou said, "I believe that as long as the Japanese government lead the public to face up to wartime history, China-Japan relations would open a new page with deep communications".