That's simply coincidental. But it is your fanfic, so do as you like. *shrugs*
Also, what the heck is up with distinguishing between the Japanese and American releases of the game? I mean seriously, the only difference is that the American version is a translation (and probably slightly localized) version of the Japanese version. So how can you draw such a distinction when there is only a very slight one to begin with? I guess I am just repeating what Ouch! said, which is a good point. If they had given Sora et al, different names then I can see the point of drawing the distinction, but this is not like the early localization of anime where they totally massacre the original work and give the characters more English sounding names.