Story - I watched this because a lot of people said not to. I just wanted to see what was so bad about it. I can see why. You may hate the very existence of the anime but you have to remember it's a based on a game which has mutilple endings so don't hate School Days just the story the anime followed. I felt bad for Kotonoha the entire series. She didn't deserve that. Ito is among one of my most hated characters ever. And I don't hate that many.
Sound - I don't remember it at all so I can't say it was bad or good so it gets a median score.
Characters - I liked Sekai and Kotonoha. But they just weren't that great to help out the overall score. I hated every single male character in this. I mean Ito's friend was just annoying because he was trying to be with Kotonoha. And Ito was just bad. But some of the blame should also be put on Setsuna for not letting him ever talk to Kota. So shes also just an all around bad person.