Last name Исао (Isao 
, Isaso 
, Исао 
) , around the globe, is quite a rare family name. The cognomen Исао is characteristic of Taiwan, where it is quite a rare surname, Israel, where it is a rare surname, and Japan. Measured by absolute frequency, it is the most numerous in India, China, and Japan. Also, Исао is the forename as well as the last name.