Cognomen Nisai (Nisai 
, นิสัย ) , in the entire world, is a rare family name. The last name Nisai is habitual in Thailand, where it is a rare surname, Indonesia, where it is a very rare surname, and Norway. Not in comparison with a country's population, it is the most numerous in Thailand, Indonesia, and Nigeria. Also, Nisai is the forename as well as the last name.