Chiyo definitely takes after Makoto. She expresses it a little differently, but I can still see it. Kanon probably worries a lot. Makoto is far too single-minded. Is Chiyo missing a lot of school, or is she getting some kind of support that makes it easier? Like Takeru walking with her part or all of the way there and back. Or something like that. I think Takeru would be a good option for that sort of thing. Akari too.

I'm sure Riko is also freaked out by the prospect of a long-time friend disappearing into another world with no way to escape or contact anyone. That sort of change is scary, and it must be even moreso if she knows Chiyo will be just as upset there.

I can see Kanon having a way to contact Alain. Her response to the Ganma world seems a lot more balanced and mature than her brother's.