maybe

[kingoflight]

http://www.youtube.com/watch?v=FZaR49v4rq8

i noticed in the video where roxas stands up and the riku comes out i think tht is after they get out of the building after they teleported him into tht realm and cuz he looks clueless the when riku comes out he gives him the name roxas and thn he goes by that

i just got tht from just a big theory please comment

[lionsbarrage]

Xemnas was the one who gave Roxas his name, not Riku.