You must have a Japanese 3DS and Japanese copy of Pokemon Sun or Moon to receive the code.
Serial code will be sent within 24 hours of receiving payment.
These Pikachu will be distributed to players who insert a serial code that will be as found on preordered tickets for the 20th Pokémon movie in Japan. The Pikachu obtained depends on the date the code is redeemed. Unlike most events, players are able to redeem multiple serial codes on the same game.