Sunset Shimmer has no memory of her life except for the last two years, she is in her early twenties.

She has the abilities to transform into Kamen Rider Symbol with Giga Memories and has been hunted by creatures called Dopants for as long as she can remember.

One day, she is pulled into a pocket dimension by the Dopants and runs into a girl called Kotori.

What is Kotori's connection to Sunset's past?