Aristeia

exactly- he wants to change the rules for himself. What if someone came to your dojo and said that where he comes from people train in black belts from day one so he would like to wear his despite only having 3 months training? would your club say "sure" or would you chuck him one of the spare white belts.

There is no valid reason for expecting an exception to the rule here. Either take off the hakama and demonstrate you're prepared to follow the rules or take your leave.

If I was the instructor I would be concerned about such behaviour from a visitor and likely be happy to see them leave. If they want to make an exception to the rules on this - what other rules may they want to import from their dojo onto my mat? If they're prepared to be arrogant and rude enough to want to insist on their way rather than my way in my dojo, how are they likely to treat their partner? It raises a host of questions....