In May 1936, Ichiki took command of an infantry battalion in the 1st Regiment of the China Garrison Army. When a company of his battalion held an exercise near Beijing (Peking) on the night of 7 July 1937, it was fired on by the Chinese. The 1st Regiment's commander, Colonel Mutaguchi Renya, then ordered Ichiki to take his entire battalion to the spot and attack the Chinese. The resulting clash is known as the Marco Polo Bridge Incident. It was the beginning of the Sino-Japanese War.
Promoted to colonel in 1941, Ichiki took command of a regiment just before the beginning of the Pacific war. His regiment was to have been a garrison force on Midway Island, but when the Japanese navy lost the Battle of Midway, Ichiki's unit was sent to Guadalcanal in August 1942. In planning to attack U.S. Marine positions, Ichiki developed tactics that took little account of Marine dispositions, and his unit was annihilated in the 21 August 1942 Battle of the Tenaru River. Ichiki's men refused to surrender, and they and their commander were killed in the fighting. In the battle, Marine losses were 44 dead and 71 wounded, whereas the Japanese had at least 777 killed. Ichiki was posthumously promoted to major general.
Frank, Richard B. Guadalcanal: The Definitive Account of the Landmark Battle. New York: Penguin, 1990.