I have been thinking this for sometime now. In this fanfic, Cinderella and the prince are friends with Ryu and Ken. Ken invites Cinderella and the prince to come to his and Ryu's world for a visit, and Cinderella decides to bring her step-family with them, hoping it would changer her stepmother's and Drizella's lives for the better. When Gile beats Ryu and Ken which leads them to go on their training expidition, Cinderella and the others come with them. Now their adventure around the world of Street Fight II V has begun.
This is what I think how the story would go. Tell me what you think in the comments below. Thank you.