My Girlfriend is a Serial Killer

Etsuro Kurosu (Yosuke Sugino) fails getting into a university and becomes a hikikomori. One day, he tries to hang himself from a hook on the wall in his apartment. He fails, but his attempt leaves a hole on the wall. Through the hole, Kurosu can now see Rio Miyaichi (Haruka Fukuhara). He becomes fascinated with the girl that lives next door. Later, while peeping at her through the wall, Kurosu sees her in the process of brutally murdering someone. He screams and is caught by her. Kurosu confesses that he loves her and they start to date. Kurosu feels happiness in his life, but what will happen to him? Will he be murdered by Miyaichi?