[Orrin]

Spoiler for Game:

Well I'm not sure about the 永遠に ending right now, I know that it involves the videotape but if i remember correctly then Kotonoha didn't get any worse treatment then Sekai gets during any other part of the game.

During 鮮血の結末 it's not like anyone does anything bad against her except for her classmates. Makoto pretty much choses Sekai and Kotonoha herself (and her classmates) takes care of the rest without them noticing.

Not to say that Sekai is perfect either, or Hikari, or Nanami, or Otome, the only one that isn't mean/extremely jealous during any part of the game is probably Setsuna. It might be that you can get the 肉欲 ending in so many ways that made Kotonoha seem so bad.