I had to watch it twice because the first time I didn’t see the last Pikachu had lagged behind and had to hurry his little legs to catch up to the others. I counted 20 Pikachu in the Pika-parade. Edit: I found a longer video that includes the above video.
But wait there’s more!
The song thats playing is “Butterfly” from Smile.dk. And one more with the same song but different clips: