The Tree of Harmony was giving off a strange reaction that the Mane 6 were sent to investigate, but when they got there, they heard a voice from the Tree of Harmony, telling them that they have a second life that they didn't know they have. So, they have been sent to the world where their second reality is. Pinkie Pie is surprised that she's on her own in a world she doesn't recognize, a different family, and the knowledge of how that world works without her knowing how she knows it.

And apparently, she woke up on the day she was about to leave for the University of San Diego, and she finds out that she's an only child. And hopefully, her roommate at the apartment she's staying at, Kevin Evers, a young man who never got a chance of fun in his life, would be able to help her with adjusting to this world, and in return, she can help him learn to have some fun.