https://www.gamespot.com/articles/pokemon-sun-and-moon-begins-next-pikachu-giveaway/1100-6453622/

To celebrate Pokemon's 20th anniversary film, Pokemon the Movie: I Choose You, receiving a limited theatrical run outside Japan, Pokemon Sun and Moon is continuing its giveaway of six special edition Pikachu in the game. Last week, players could get a Pikachu wearing Ash's original hat from the TV series. This week, you can input a code to get a Pikachu that wears Ash's hat from the Hoenn region (the first time he changed his hat in the series).

This special edition Pikachu also comes with a set of moves inspired by those attacks used in the Hoenn region. The moves are: