Can You Name the Character-Inclusion that this New Kingdom Hearts Trailer is Showcasing by the Music?

Ever since Kingdom Hearts 3D: Dream Drop Distance was announced for the Nintendo 3DS a couple of months back, it seems that we keep getting the same couple of scenes teased to us relating to Neku from The World Ends with You being included in the game, alongside all the previously shown off Final Fantasy et al characters that have been added in the last few games. Nothing all that special from this trailer, but worth watching if you haven’t seen anything on this game before.