Mirai's Sister

As some of you may already know by reading Mirai-chans story, Mirai has a younger sister.
Azami sensei and I will begin designs on her shortly and wanted your input on the following:-
1. Mirai's sister is tentatively named "Kako" meaning "the past" as Mirai means "the future." But Kako is probably not such a nice name to have so am currently thinking of a name that goes well with Mirai. Was thinking maybe Shorai [将来] which also means "Future." Do you have any suggestions?
2. What sort of school uniform? Mirai is high school and her younger sister would be secondary school so their uniforms wouldn't be the same.
3. Pose - what sort of suggestions do you have?

Take into account that the last time I asked you, most of you said that Mirai's sister should be about 12 or 13 which I think is fine. I also like the idea of pony tails too.