Family name 正之 (Masayuki 
, 正之 ) , around the globe, is quite a common surname. The family name 正之 is habitual in Japan, where it is quite a rare surname, Taiwan, and Singapore, where it is a rare surname. In absolute terms, the name is most common in Eastern Asia, particularly Japan, China, and Taiwan. Also, 正之 is the forename as well as the last name.