Check character: I'm not confident my glance at the Magia Record character page is sufficient for those two furthest in the back in panel 2. [EDIT] After uploading all the henshin animations, one glance at that panel was enough to know who they were.
I actually don't know if this is technically a school uniform since I can't read Japanese. If someone can translate and correct the tags, that'd be appreciated.
Before trans: I'm guessing G-chan is telling her big sister about her day, but G-nee isn't really listening, just thinks her little sister is cute?
Not quite, I think its more like G-nee made a big-sisterly conclusion about G-chan's feelings toward humans. By the way, thanks for concluding the left figure is G-buri's big sister. I was initially confused by this comic (thinking the right figure was Cricket-chan returned), but that makes the most sense. While G-nee looks mostly like G-buri, her bow is a different pattern we haven't seen before.
(G-buri's exasperated expression in the last panel looks a lot like Cricket-chan's common expression, but Cricket-chan's bow has an ornament we don't see here.)
Kangaroo Keeper: "Aren't they beautiful?" Cassowary Keeper: "Why am I nervous, I TAKE CARE OF DUCKING CASSOWARYS!" Penguin Keeper: "N- Nice but Penguins are better. I am the duckdamn Penguin Keeper."
