Family name Kihai (Кихай 
, Kihai 
, Кихаи ) , around the globe, is a rare last name. The surname Kihai is characteristic of Russia, where it is a rare surname, Kazakhstan, where it is a very rare surname, and Tanzania. Not in comparison with a country's population, it is commonest in Russia, Tanzania, and Ukraine. Very seldom, Kihai is the forename as well as the last name.