help!!

hey i’m trying to find this bl! all i remember is that the ml gets trapped in a book that his childhood friend made and then he falls in love with the ml only for the childhood friend to get jealous and kill him.. theeeen he gets brought back into reality and then the best friends sister and the ml plan to trap him back (ml) into the book and drop the book in the ocean so that the childhood friend doesn’t bother him again…