In a past quick tip I have mentioned that Seller Central is in Japanese and English. And then they added Chinese a few months back.
I think it happened from today, but now they have added German, Spanish, French and Italian!
*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!