I would like to see Mushroom Princess Miabell Luna Tearmoon setting out on an expedition from Miatown and finding through some shenanigans the portal gate to Rosemyne’s Alexandria. From there there would be clashing ideologies between the blind faith of Miabelle’s followers and the extreme competency of Rosemyne’s. All while Mia and Myne are happily exchanging ideas and generally getting along like a house on fire.
Honestly I just don’t remember if Miatown had a port or not? But thanks to Alexandria’s portal gate this is something that could easily be written around: “Suddenly a magical gate appeared in Miatown with a vast body of water on the other side. Mia had a ship build and set out to explore the town visible in the distance. The lure of new and tasty snacks was just too stong to resist.”
Mile meeting Hannelore would also be an interesting pairing with their love for adventure stories.