Surname Онаи (Onai 
, Онаи 
) , all over the world, is a rare family name. The surname Онаи is habitual in Ghana, where it is quite a rare surname, Tanzania, where it is a rare surname, and Georgia, where it is a very rare surname. Not in comparison with a country's population, it is commonest in Ghana, Tanzania, and China. Also, Онаи is the forename as well as the last name.