Across Asia, this gift has been given out as serial code for either ordering or pre-ordering the tickets to M21: The Power of Us.
This gift can be redeemed by US 3DS (regardless of language), EU 3DS (ENG, JPN, KOR, CHS, CHT), JP 3DS and TW 3DS.
This card only comes in Japanese, despite being accessible by those devices.
As of December 1st, it's confirmed that the gifts are receivable in game.
The Taiwanese code card indicates the last day of redemption would be March 31st, 2019.
The redemption dates on the Singaporean code card indicates the event runs from December 8th, 2018 to February 28th, 2019.
It is not clear which end date is the correct one (as both events ARE the same).
Format Ver.1.0.6-3, Post Updated Date:20181201_0653