Sometimes it feels like rather than her not belonging to this place. It was Akito who didn't belong here. While Akito understands the customs of this place and has lived here for so long. Setsura felt like he didn't belong here. After thinking such things, Setsura would play with the idea of Akito in the future - in TOKYO. Strangely enough, it felt so real. Akito going to school, working in the modern-day police force, living together with her.
But, 'That's wrong.' The reason why she can envision those things so clearly is because of him, right? Since she has a beloved person in the future, she could easily swap the image of the two out with one another. Those imaginations regarding Akito maybe her memories of that person. How awful of her if that were really the case.
Sure there are times where she thinks Akito and that person is alike.