Cognomen ハガイ (Hagai 
, Haggai 
, ハガイ 
) , all over the world, is quite a common surname. The family name ハガイ is characteristic of Israel, where it is quite a common surname, Namibia, where it is quite a rare surname, and Kenya. Measured by absolute frequency, the name is most common in Israel, Nigeria, and Kenya. Also, ハガイ is the forename as well as the last name.