¥3,000 "registration fee" that appeared on the bill out of nowhere

never heard of a registration fee before. wasn't on the menu, wasn't mentioned when we sat down, just appeared as a line item on the bill 🚩🚩 asked about it, staff said it's standard for new customers. paid it because it was only ¥3,000 but it set the tone for the rest of the bill. red flag i should've acted on immediately