In 1941, the Imperial Japanese Army had a total of 1,700,000 men. At the beginning of WWII most of the Army’s divisions were stationed in China and (for fear of Soviet invasion) along the Mongolian border
In 1942, soldiers were sent to Hong Kong, the Philippines, Thailand, Burma, the Dutch East Indies and Malaya.
By 1945, there were 5.5 million men in the Imperial Japanese Army.
Beginning in 1943, largely due to shipping losses, Japanese troops were short of supplies, especially food, medicine, munitions and armaments. Many fighter aircraft become unserviceable for lack of spare parts and many military deaths resulted from illness or starvation.
Source: http://en.wikipedia.org/wiki/Imperial_Japanese_Army#World_War_II