it seems like the real competitive asian mma promotion is One while rizin is more into entertainment .part of what is holding them back is an archaic deal with fuji tv (or so i have been told by r/rizinff). there are a few stand out japanese fighters like the asakura bros but a lot of them are ham and eggers brought in to lose.i dont know that they do have cash laying around anymore either. before the last event they had a crowd funding campaign to raise money to cover the costs of putting on the events