Thanks for the translation! That was a fun story!
Overall, the translation was really good. But, Prince Yvonne…
You might want to check that name. "Yvonne" is the feminine form of "Yvon" — while the vowel changes in French, in most languages, including English, they're pronounced the same (and Japanese would mangle them the same).
Maybe it's because I know French, but that was distracting.