To be in a border town, to feel the tides of citizenship change. To be caught in that fairly consistent tug of war between nations. Kalgan's parents had been Kouka citizens once, and their tired eyes still drift across that river and see land that once they could easily walk to, friends and maybe family across that boundary.
Kalgan may be young, but he definitely knows he's missing out on something, and it isn't only his parents' eyes that wander from one kingdom to the next, but the whole town does too.
Kouka must be something special to leave this town feeling alien under Kai's rule but also achingly familiar the way that things come to be, when you are much too tired to fight anymore.
So, Kalgan crosses that boundary, sneaks right over, and feels alien in a place that his parents must know and remember fondly, a place he's yearned to reach, a place his family and town in the Kin Province still yearn for. And he meets strange but kind people. Is this what Kouka Kingdom is like? Warm like family but also strange and different.
Soon, Kalgan will be a Kouka citizen for the first time and no longer just a Kai citizen. And that will be both alien and comforting, something new and surprising but also familiar in a way that's kind of hard to explain. But Kalgan will still smile when he thinks of his first friends from Kouka, an odd bunch that feel a lot like family, a group he was sorry to get sick, and yet they never blamed him either.
His town won't change despite their new yet old country of origin, but there will be new places to go, and unfamiliarity will even be given a chance to become familiar finally.