Isao Kato graduated from the Military Academy in 1900.
After graduating from the Military Academy was sent to join the Japanese garrison at Tientsin, China (1903). After the Russo-Japanese War (1904-1905) was appointed teacher at Staff College and became friendly with Sun Yat-sen and other Chinese refugees in Tokyo. When in 1908 the Chinese Emperor died, Kato joined the movement of Chinese revolutionaries in Japan and as a result was dismissed from the government service. In 1909 Isao Kato left for China where he taught first at Kwantung and then at Yunnan, but all the time he was keeping in touch and working actively with Chinese revolutionaries. When the revolutionaries rose in arms at Yunnan, he came out in the open and fought alongside them (1911). However, he was killed during a riot.