Family name 亚凯 (亚凯 
, Yakai 
) , throughout the world, is quite a rare last name. The family name 亚凯 is habitual in Japan, where it is a rare surname, China, where it is a very rare surname, and Malaysia. Measured by absolute frequency, it is commonest in Japan, China, and India. More frequently, 亚凯 is the forename as well as the last name.