Last name Kousei (コウセイ 
, Kousei 
, Кусей 
) , around the world, is a common cognomen. The family name Kousei is habitual in Japan, where it is quite a rare surname, Myanmar, where it is a rare surname, and Indonesia, where it is a very rare surname. Measured by absolute frequency, this name is the most popular in Japan, Indonesia, and Russia. Much less frequently, Kousei is the forename as well as the last name.