Serebii Update: The Six Ash Pikachu have been confirmed for distribution for Sun & Moon to tie in with the movie https://t.co/oV6DIIA7Ub pic.twitter.com/fuoqo7YS2i
— Serebii.net (@SerebiiNet) March 12, 2017
The hat worn by your Pikachu is determined by when the code is redeemed, specific dates for which can be found here. Players will also receive the Pikashumium Z-Crystal, which allows Pikachu to use its special Z-Move, 10,000,000 Volt Thunderbolt.
This isn't the first time Pokemon fans have had the chance to get a special hat-wearing Pikachu. A Santa hat-sporting Pikachu was available in Pokemon Go late last year, and a festive party hat-wearing one popped up in the aforementioned mobile game just a few weeks ago.
There's no word on when or if the Ash hat-wearing Pikachu will be making its way to territories outside of Japan. While I Choose You opens in Japanese theaters on July 15, The Pokemon Company has yet to announce plans to release the film in the west. Alex Osborn is a freelance writer for IGN. You can follow him on Twitter and subscribe to his YouTube channel.