This came up as a question today, so I’ll highlight the answer here.
It’s not a requirement for Amazon jp.
Obviously you should have one, but Amazon does not require it. I’ve checked this with Amzn support. Hard to believe…
*This post originated from a post in the Amazon Japan Facebook group, “Amazon Japan PL”. The information may well have changed by the time you read this. Please check the DATE of the post before you make any decisions based on this information!