@Raww Le Klueze
That's kinda what I'm getting at. While Riou didn't chose Tomo's star directly nor knew knowingly his choice would affect her you can't really deny that he's the main cause for it.
Yes I'm basically assuming that stars are decided from birth like with the zodiac, I could of course be wrong since it's not fully explained in the games. I'm simply going from what I think would be the most logical thing to say in the situation.
- Gensopedia offers some trivia on a few stars e.g. "the path of the Tenei Star (Gremio, Lyon) can be seen following another star in what seems to be a protective manner".
- In SI Leknaat is a seer and uses astrology to see possible futures.
From this info I assume that the stars are moving in certain paths over the sky and when a person is born they're assigned the star that's above them at the time. And here is where Tomo comes in. Either she would have to have been born when two stars were alligned, or she was born right in the middle of a shifting timeperiod between two stars.
My theories are complicated I know, but I'm just the kind of guy who likes figuring these things out.