Hmmm, it's reasonable to think that the Sunglasses Guy (SG from now on) could be a partner of Akiyama, but I wouldn't trust in someone like Akiyama if I was SG, so I still have doubts about that. Besides, Akiyama said loud in front of those 3 that he would win, this situation is a bit weird (too theatrical, in any case). Basically, if he and SG had a plan, he wouldn't say it so loud that he would win, they (SG and Akiyama) would remain quiet and finally win.
So... I think Akiyama is playing alone here, but I guess he'll give any other one its money part (to all players) and finally go to the next round.