Yep, Asagi and Fuuka are Ena's sisters. How about we use the Haze Go Club for them?

Kaneko is a bit Asagi-like - older sister-ish because she's smart and good at go, a bit sneaky, a bit bossy, but ultimately a generous person. As for Fuuka, um, maybe Mitani? Because Asagi kind of bullies Fuuka, and Kaneko bullies Mitani. :D

Wait, this is getting weird. Fuuka hangs out with Yotsuba a lot, kind of baby-sits her. So...Mitani would baby-sit Akira. MAYBE IT'S RETHINKING TIME.