"Niryuu Shousetsuka: Serialist" is based on David Gordon’s 2010 mystery novel “The Serialist”. Ippei Akaba is a failed novelist who now writes serialized erotic stories for a living. His luck seems to change when he’s contacted by a notorious serial killer on death row who offers his story in exchange for some personalized erotic fiction involving his female devotees.
However, Akaba soon finds a headless corpse left in the same manner the serial killer would leave his own victims. Police suspect Akaba, who suddenly finds himself on the run as he attempts to track down the person who set him up.