Last name Tetsuya (Tetsuya 
, Тетсуя 
, Тэцуя ) , in the entire world, is quite a rare surname. The last name Tetsuya is characteristic of Japan, where it is quite a rare surname, Singapore, where it is a rare surname, and Indonesia. Measured by absolute frequency, it is the most numerous in Japan, China, and Indonesia. Also, Tetsuya is the forename as well as the last name.