What you describe is a customer rating system, it's a nice idea in theory and doesn't necessarily have to only be for Indians, it could apply to everyone. It won't work since that's too much administration overhead for the shop unless they build a good computer system which we all know they can't do, since their website is still garbage. Plus they still will have to convince some FOB asian girl to erase their preconceived ideas of Indian men. It's not Ginza management you are trying to convince, its the girl, if it was up to Ginza management they wouldn't have any restrictions on customers.

If I was Indian I would just do RNT and try to get upgrade extras through this way. The reason being is RNT girls don't have such a strict "no indian" clause since its YMMV. Once you meet the girl you can work on your reputation with her.