I hate Setsuna because she was the only person that 100% knew the truth and could have told Sekai (and she may have listened), but didn’t tell Sekai about it. I mean, Sekai KNEW, but it would have been different to have your best friend in the whole world tell you, as opposed to all the miscellaneous whores in your school… but instead she ran away after sleeping with him and actually told Makoto to stay with Sekai after that. What the hell kind of person tells a cheating, sociopathic, narcissistic sex-addict to stay with their sister?
She’s actually Sekai’s half-sister, which they never mention in the anime. Doing that to your sister is just too messed up.
That’s not even mentioning the way she treated Kotonoha, claiming that it was for Sekai, but it was really just for herself in the end. I really love Sekai and Kotonoha both, so seeing her treat them that way is just meh.
Also - and this is just personal - I seriously hate seeing her in any sexual situations since she looks 10. Her eyes were cool, but that was it.