Imagine, for a moment, if you fell asleep watching one of your favorite anime series, and then you wake up in said series. Now imagine if said series was infamous for having some of the most shocking twists of recent times.

Well, one young man finds out what happens in this unlikely scenario when he wakes up as a first-year background character in the popular action-fantasy-horror anime series Rimnan Castle School. When he realizes where he is, he becomes determined to change the course of the story. As he does, second-year student Lena Vale catches his eye, and the two begin to grow close despite his own ideas of who she should be with as a fan of the series.

However, it seems that every time he solves a problem, something else in the anime's world goes wrong. With this in mind, he faces a crisis. Can he save the characters he loves without destroying everything else? Will he be forced to let some die to save the rest?