In fact, every girl is a princess, living in the dream castle she has compiled for herself, waiting for the day when her destined prince will come here, draw his sword and cut off the dense thorn bushes covering the castle, and then take them away.
Maybe the princess will meet her favorite knight and spend her whole life pursuing it.
Fairy tale books are full of various ways for princesses to meet princes or knights, but none of them hint to Erwin how to find his own unique princess.
Conception: