The running gag of this series is that Chio is actually really plain or borderline ugly, but man she's drawn way too cute.
I'm pretty sure the joke is she's just plain, but Manana is kind of an asshole that thinks everyone views her as ugly while also wanting to protect her from that. Manana is both a saint and prick all in one.
Also man it feels good to end the dry spell after all these months.