 At the start of the Second Sino-Japanese War, Chō was commander of the IJA 74th Infantry Regiment of the Shanghai Expeditionary Force, attached to Japanese Central China Area Army, and based in Manchukuo.At the Battle of Nanjing, he was aide-de-camp to Prince Asaka and is thought to have been complicit in ordering the massacre of prisoners of war, but it is disputed whether he obeyed an order from the prince, or whether he acted on his own.Chō was subsequently involved in a number of border incidents between Manchukuo and the Soviet Union as Chief of Staff of the IJA 26th Division from 1939 to 1940.