'Promise you will never leave me' is a Haikyuu!! fanfiction, more precisely a Yandere! Terushima x OC. I am writing this for a friend (it was supposed to be a draft but she asked me to make it into an actual story). ⚠️Warning⚠️: In this story there will be mention of gore/violence,strong language and maybe hints to sexual stuff (you know,the adult stuff) Read at your own risk! It's my frist time writing, so please bear with me. English isn't my main language, sorry if there are any mistakes. Criticism is welcomed. Updates will be slow, because school is about to start for me. I own nothing, except for the plot of the story and my OCs.