I asked for some time to talk to my parents. I wanted to ask for an explanation because my parents didn't give me any explanation until now. They only said that I had to leave Birwick to go to Northendell.
My father said this was the consequence that I had to bear. If I didn't let Mirai escape then, maybe I could still play in the castle with my friends. It turned out that without me knowing, my father had made a deal with Northendell. He had made a deal with King Theodore of Northendell that I would marry that man, and in exchange for that, my father wanted King Theodore not to touch Birwick at all.
Birwick would remain an independent kingdom despite the ongoing conquest of the small kingdoms by Northendell. It never occurred to me that I would be used as a political exchange.