Getting back to the question about why a "Humanities Visa or Entertainers Visa" wasn't acceptable. I am pretty sure that since the celebrant can make a lot of cash the Immigration bureau want to control who can be doing the job. It doesn't take much for them to crack down on the number of foreigners coming to japan to make money. It might seem pretty arbitrary to some but by making it harder for foreigners to get jobs here there will be fewer foreigners coming in the first place. That is the mentality for some here.
I am also a celebrant and know that where I work they won't even accept a valid working visa believe it or not. Only permanent residents.
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