Well, saw the amnesia coming a mile away. A bit too cliche to be honest.
So, yeah, we have confirmation that Reiichi doesn't really love his wife and is an unreliable asshole that cheated on her from day one.That Risako is a bitch that cares only about herself and probably had a casual relationship with Reiichi since High-School and was secretly snickering at Kaoru's love antics.
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.
The joke is also that Manana thinks very highly of herself (in the imagined comments, someone says she must be an actress).