How about a series of 6 islands in the Pacific, one for each style (plus one for any special styles)? Think about it, there could be a 1A island for 1A throwers, a 2A island for primarily 2A players, and so on and so forth. And everything would be made out of, or at least resemble, yo-yos. It’d be beautiful.
The only problem is that if island rivalries start escalating, then the 2A lot would prove a formidable force to overcome. You wouldn’t even be able to get near them, and I question how well the ranged 4A attacks would work against the constant barrage of loops…