 If you liked
Shinsekai yori
|
 ...then you might like
Kuzu no Honkai
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Characters are similar to Shinsekai Yori protagonists (appearance and nature).
They don't know what to do. And of course sex. They are young and inexperienced. In addition, their relationship is complicated. If you aren't satisfied with this in Shinsekai Yori, you must watch this.