Cheren looks like he's one not to be messed with, but Belle looks like the one that would come out on top. I don't know, I think she will come out and suprise us all and become the champion or something!
N, mysterious looking, but I'm sure he will be the more serious rival, while Cheren and Belle are just friendly battling.
Makomo, she won't have much of a role in the game will she?, It will probably be like Celio, introduced by someone (in this case Araragi) and show you something (in this case the High Link or whatever) and then not do anything.
Araragi, love. The first in-game female professor of a reigon.
Dento, I will have to see more about, he's not top of my list
Aloe, she looks unique from the other gym leaders we've had before, and the first cook, No? (I'm not counting Brock seems that's in the anime).