This title is also often given to Gichin Funakoshi because of the latter spreading karate throughout Japan, but only after Ankō sensei had introduced the art of Okinawate to the country.

[3] Itosu served as a secretary to the last king of the Ryūkyū Kingdom until Japan abolished the Okinawa-based native monarchy in 1879.

In 1908, Itosu wrote the influential "Ten Precepts (Tode Jukun) of Karate," reaching beyond Okinawa to Japan.

Itosu's style of karate, Shorin-ryu, came to be known as Itosu-ryu in recognition of his skill, mastery, and role as teacher to many.

Itosu's students included Choyu Motobu (1857–1927), Choki Motobu (1870–1944), Kentsu Yabu (1866–1937), Chomo Hanashiro (1869–1945), Gichin Funakoshi (1868–1957), Moden Yabiku (1880–1941), Kanken Toyama (1888–1966), Shinpan Shiroma (Gusukuma) (1890–1954), Anbun Tokuda (1886–1945), Kenwa Mabuni (1889–1952), and Chōshin Chibana (1885–1969).