Regarding tax on a large monetary gift from overseas (New Zealand) – Non-heir inheritence

Hello, have a few questions regarding the tax process and how best to handle a decently large sum of money coming into Japan from New Zealand.

Essentially, my grandmother died a few months back, and her estate has finally been settled. Her heirs were my father and two uncles. I myself wasn't named in the will, but my father is gifting me $20,000 NZD (approximately 1,700,000-2,000,000 JPY).

I have currently been in Japan for 9.5 years, and am on an instructor Visa (will be applying for PR next year, but chance I won't get that due to ALT income).

Can anyone shed some light on how best to bring this money into Japan without half of it being eaten by taxes? I know some will need to go to taxes which I am fine with, but just trying to minimize it where possible, and how to get it all processed correctly.

I was also unsure if this would be considered inheritence, or a monetary gift due to how it is being sent to me (as mentioned above).

From my research online, it looked like if I have been in Japan less than 10 years the taxes would be less than if I left it till later?

Appreciate any help with this!

by Drar