Yeah I did when it first released. Don't remember all of the steps honestly but I had to create a Japanese google play account, and setup an address in Japan within the Google accounts settings (No VPN needed). If you're on iOS I believe it's the same idea but you might need a Japanese gift card to the apple store.
Thanks a ton for doing this! Big fan of dqmj3p and it works great. I don't know any Japanese and I'm very unfamiliar with 3ds modding but I can most likely update the json with a quick script that uses the google cloud translate api to get just direct google translation of the Japanese for all the missing fields. If I did that would you be willing to redo the patch with those translations? (Or if you could point me in the direction of some sort of documentation converting mes -> json and back)