Yet another question about bringing gold into Japan

My wife (foriegner) is going to move to Japan soon, and she owns a decent amount of 21K gold as jewllery that she plans to bring with her (no gold bars or anything crazy like that). In the previous posts that I searched through here, the value of gold in questions was always around the limit set by customs (200k yen) so it was pretty vague on whether to declare it or not.

With the crazy high gold prices recently, I calculated that the value of the jewllery alone would be around 2 million yen, with the heaviest item being a 60g necklace. Also, we plan to bring some grams of 21k gold coins (old family gifts, nothing bought recently).

I fully intend to declare the gold coins and (begrudgingly lol) pay the 10% tax on them if asked to do so, but when it comes to the jewllery, I am unsure of what to fill in as they are personal use items that she enjoys wearing and that we hope to never sell.

Is it better to just declare every piece of gold she has, including the rings and earrings? Or how should we proceed from here? I tried looking for the official government documents surrounding this but found nothing appropriate unfortunately.

Bonus question: if we, for whatever reason, have to leave Japan with the gold we already paid taxes on, do we get the money back without selling the gold itself?

by No_Abbreviations_286