Family name Koyanagi (コヤナギ , Koyanagi , Коянаги ) , worldwide, is quite a rare cognomen. The last name Koyanagi is habitual in Isle of Man, where it is quite a rare surname, Canada, where it is a rare surname, and Singapore. Not in comparison with a country's population, it is commonest in Japan, the United States, and Indonesia. More frequently, Koyanagi is the forename as well as the last name.