so. the literal title translates to ‘from the new world’. its written (in-universe) by a woman named saki, as she recounts the events of her youth and young adulthood.
the world of shin sekai yori takes place 1000 years in the future, which from now on i will call ‘now’. so 1000 years ago (our present day), people with PK, or psychokinesis, began appearing in the world. many people without PK are fairly anxious about this development, especially considering that many people with PK are criminals, with the ability to kill hundreds of people at once. for centuries, there are endless wars as people with and without PK try and find stability in a world that has been ravaged by nuclear war and mass murders.
there is now something called ‘death feedback’- essentially, if a normal human with PK kills another human, they die. this can be circumvented by being a fiend (someone with intense violence impulses, no connection to other humans). there are also people called karmic demons, whos subconscious cantus have started warping the world around them to a severe degree. for some reason its fine if your cantus changes the world around you just a little bit.
saki is on ‘team 6′ at school, with satoru, shun, mamoru, and maria. there was another girl, but she went away.
saki lives in a place called ‘kamisu 66′, which is a ‘society of love’- essentially, a human society modelled after bonobos (emotionally unhealthy for humans) where whenever someone gets too stressed, other people use sex to try and calm them down. this is so engrained in society that children (children-children, i mean) do it. because it is so common, prepubescents and people going through puberty are encouraged to have same-sex lovers. note: yusuke kishi (actual irl author of shin sekai yori) is a huge homophobe.
WHAT IS SHIN SEKAI YORI ABOUT, LIKE, THEMATICALLY: nature vs. nurture, emotional distance vs. the desire for emotional intimacy, eugenics, individualism vs. collectivism, human rights, fascism, the loss of the safety of childhood vs. were you ever safe in the first place
i dont know how much detail you actually want, but this answer was originally over 5k words long. so i trimmed it a lil bit. anyways its so good but so madness inducing theres a free fan translation if you google ‘cadetnine shin sekai yori’. its so good cecily i mean it its SO good. its so good. read it. its so good.
trigger list: blood, gore, violence, torture, animal cruelty, underage sex, body horror, child death, hypnotism, child grooming? it can also be somewhat paranoia inducing for me at the very least.
and i am NOT kidding abt the blood/gore/violence/torture/animal cruelty. if youre sensitive to any of those things i would say you should be like, either very wary or not read it at all. i would say its better to read it than watch the anime (which was mostly faithful except in one pretty big way), since the violence isnt actually seen when reading.