My Girlfriend is a Serial Killer (2019)

Etsuro Kurosu faills 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 in the wall. Through the hole wall, Etsuro Kurosu can now see Rio Miyaichi. He becomes fascinated with the girl that lives next door. Later, while peeping at her through the wall, Etsuro Kurosu sees her in the process of brutally murdering someone. He screams and …