There's one problem with me making the opening post:
I can justify Mikael being where ever. Most other MW characters have no such luxury. It is entirely possible for them to start separate, but at least the japanese cast could be centralized to a location.
For example, the students - do they attend the same school? It doesn't have to be a fictional one, we could as well use any existing Japanese town for this.
So it'd be better for one of the student characters, like Sora, to set the scene.