Surname Wataru (航 
, 亘 , Wataru 
, and others...) , in the entire world, is a widespread cognomen. The cognomen Wataru is habitual in Japan, where it is quite a common surname, China, where it is quite a rare surname, and Singapore, where it is a rare surname. In absolute terms, the name is most common in China, Japan, and Indonesia. More prevalently, Wataru is the forename as well as the last name.