"Sen Bir Tanesin" is the ninth single by Hepsi.
The song was recorded for the Turkish version of the Winx Club Movie soundtrack.
"Sen Bir Tanesin" was recorded with another song for the soundtrack called "Sadece bir kiz", however this song is more typical of the group as it is a ballad.
The music video sees the girls in rocky clothes performing at a car garage.
Scenes of the Winx Club Movie cut in between the performance.