This event was distributed to commemorate the Japanese Cinematic release of Pokemon the Movie 20: I Choose You!
Serial codes for this event were being given away for pre-ordering the movie tickets, and another Pikachu can be redeemed if you have another code.
These serial codes are region locked to Japan 3DSes only.
This page hosts all of the Ash Cap Pikachu that is programmed into Pokemon Sun & Moon, in one .rar!
Distributions of the same event: