Cognomen Тацу (Tatsu 
, Tacu 
, Тацу 
) , in the entire world, is quite a rare surname. The surname Тацу is habitual in Moldova, where it is quite a common surname, Romania, where it is quite a rare surname, and Taiwan, where it is a rare surname. Measured by absolute frequency, it is commonest in Romania, Moldova, and Mexico. More prevalently, Тацу is the forename as well as the last name.