Doesn't Kagura hate her mom? Why does she sympathize with her at all? Why can't Kagura treat her mom in a cold, dyspassionate nature, and even want to make her pay for being so abusive?
Because abuse doesn't always work that way? It's actually pretty common for the victims of abuse to blame themselves, or at least be reluctant to blame the one that's actually abusing them. She probably really loves her mother(what kid doesn't?) despite the horrible shit Shinzen puts her through and despite knowing(at least on an intellectual level) that her misery is because of her mom. Seeing Shinzen die by Suitengu's hand in that Alas, Poor Villain moment probably made her seem more sympathetic, too.
Or maybe Kagura is just plain stupid.
Does Japan not have an age of consent or something? I'd think Saiga telling people that Kagura's only 15 would be enough to get them off his back about whether they're dating or not. This is an anime about the evils of depraved fetishes after all.
Japan's age of consent depends on the prefecture; it can range from 14 to 20, I believe.
In episode 16, which is a recap episode, how come they didn't count the money Shinzen used to bribe Kagura's teacher?
Why didn't Suitengu make any effort at all to recuperate Yui once he found her? Sure, she clearly didn't remember him and was severely damaged, but he literally gave her a few minutes to try to react to a toy she hadn't seen for over a decade and a brother that looked completely different, before writing her off as a lost cause. He could have at least tried to put her through rehab and/or therapy.