Last name Masukawa (益川 
, Masukawa 
) , in the entire world, is a rare cognomen. The cognomen Masukawa is habitual in Hong Kong, where it is a rare surname, Canada, where it is a very rare surname, and the United States. In absolute terms, the name is most common in China, the United States, and Brazil. More frequently, Masukawa is the forename as well as the last name.