Cognomen としあき (Toshiaki 
, としあき) , throughout the world, is quite a rare last name. The surname としあき is characteristic of Japan, where it is quite a rare surname, Singapore, where it is a rare surname, and Belgium, where it is a very rare surname. Not in comparison with a country's population, this name is the most popular in Japan, China, and Indonesia. Very seldom, としあき is the forename as well as the last name.