Blader DJ

He calls the bladers to begin matches by saying the all important 3-second countdown phrase before saying "GO SHOOT!" in the Japanese version or "Let It Rip!" in the English version. He also commentates on what's happening in the battle for the audience and viewers at home. His role is to entertain the spectators beyond the actual beybattles. DJ represents the rules of the Beyblade play, so he is more or less indignated if they are not respected. He is very 'hip-hopish', often holding out typical, respectful hand signs for this style.

(Source: Beyblade Wiki)

Note: He's not the same character as the Blader DJ from Metal Fight Beyblade.