If you are submitting evidence, I suggest you post a photo showing a piece of paper with the "date" and "krautchan" written on it, together with the "most recent dated receipt you have".
I think you should hide the "name of the restaurant" on the receipt. But please do not hide the date part.
I think this is the safest way.
By the way, I honestly don't care if you are a "real Japanese" or not.
But I think some people do care whether you are really Japanese or not.