Forcibly
Deep down, whether he knew it or not, all Giroro really wanted was to have no choice in the matter.
He wished he wasn't able to say "no" to her so often, or to cast her aside for the sake of his mission. But that was who he was, and who he always had been; a warrior. That was the only choice he'd ever make.
But someday, maybe Natsumi would find a way to take that choice away from him; to find a way to steal everything he'd ever held as important in his life as a soldier.
If she could do that, he'd follow her to the ends of the galaxy.