This novel is written by the same author who wrote the script for the TV series, and in fact, follows the exact same storyline, except with extreme personal touches. The whole story is told from first person perspectives of Kotonoha and Sekai. You can see, and almost feel, what went through their minds each time Makoto did something bad.
Being a regular sized book, it's not hard on the eyes, and combined with the fact that the story is already known, I had a pretty easy time reading it. I understand that some people find School Days story to be trivial, too offensive, or both, but if you see it as an interesting and twisted reality, like I do, you'll likely enjoy this novel. But, I'm not so sure if it'd be enjoyable to people who did not watch the anime.
