Japanac

1. Japanese man
   Moj kolega je Japanac, ali odlično govori srpski. — My colleague is Japanese, but he speaks Serbian very well.
   Grupa Japanaca fotografisala je Kalemegdan. — A group of Japanese tourists were taking photos of Kalemegdan.

Written with a capital letter (Japanac); a woman is Japanka, the adjective is japanski.