Disclaimer: I don't own Yu-Gi-Oh or any of the related characters, games, shows or writing. I only own Karu, and any other characters I might choose to add through out the story.
Now, almost anyone who knows about Yu-Gi-Oh knows about the story between Yugi and Pegasus. And how Seto, Mokuba, and Yugi's grandpa got their souls taken from their bodies.
Let's forget a little of that.
In my story, most things happen the same way, except for a few things.
1) Bakura does not try to take Mokuba's body.
2) A girl, Seto's age takes Mokuba, when the others go to find Pegasus, and she takes him up to her brother, who is on the balcony, still without a soul in his body.
So now that you understand that part of the story. We are going to a time, after everyone gets their souls back, and they leave the island, but before Battle City. Karu is the main character in this story; well besides Seto.
So who exactly is Karu?
What role does she play?
To answer these questions, I can only tell you to read the story.