Guangdong
Guangdong (; formerly romanised as Kwangtung or Canton Province) is a province in South China, on the South China Sea coast. Guangdong surpassed Henan and Shandong to become the most populous province in China in January 2005, registering 79.1 million permanent residents and 31 million migrants who lived in the province for at least six months of the year; the total population was 104,303,132 in the 2010 census, accounting for 7.79 percent of Mainland China's population. This also makes it the most populous first-level administrative subdivision of any country outside of South Asia, as its population is surpassed only by those of the Pakistani province of Punjab and the Indian states of Bihar, Maharashtra and Uttar Pradesh. The provincial capital Guangzhou and economic hub Shenzhen are among the most populous and important cities in China. The population increase since the census has been modest, the province registering 108,500,000 people in 2015.
The Battle of China
The introductory maps shown in the film show "China" as divided into "China Proper" and four outer provinces, namely "Manchuria", "Mongolia", "Sinkiang" (Xinjiang), and "Tibet". The very concept of a "China Proper"—either presently or historically—remains highly debated. The Japanese puppet state in Manchuria is discussed but never treated as actually separate from China. 
The borders of the outer territories follow the claims of the Republic of China, which means "Manchuria" includes some territory now administered by Russia and the film's "Mongolia" is Greater Mongolia, including the Qing and Republican province of Outer Mongolia (now the independent state of Mongolia) and including Tannu Uriankhai, now administered by Russia. Minor borderlands of Afghanistan, Pakistan, and India are also claimed, as well as large areas of the Tajik province of Gorno-Badakhshan, the Indian state of Arunachal Pradesh, and the Burmese state of Kachin.