Prescription of Hell.Black Label is sent to kill the corrupt businessman Hideo Aranami and its newest member, Arashi Mikami is the intended executioner. Unexpectedly Arashi gives his target a gun to see if he will end his own life, only for Aranami to try shoot him. Realizing Aranami is beyond saving, Arashi kills him. At Black Label's hideout, Mikoto Kiba questions Arashi's actions while they shower and discovers that Arashi's body is covered with scars. Taisei Aranami, Hideo's equally corrupt son, alongside his accomplice Jin Masaki kidnap and torture a man and his daughter for trying to turn secret documents of the Aranami Company to the police, but they are interrupted by detective Isoroku Tatara. Black Label storms the building and Arashi kills Taisei. A gunfight occurs and Arashi ends up saving Tatara, but Masaki kills one of the hostages and escapes, while Oriha Nashida destroys the building with explosives. As Black Label leaves, Mikoto remembers how Arashi told her that his body was severely damaged during a terrorist attack and in order to save his life, Dr. Masamune Mochizuki, the founder of Black Label, transplanted organs from his own son and Arashi's best friend, Ryu Mochizuki (since he was brain dead from the incident) and he isn't sure how much of his body remains his. Meanwhile, Masaki swears revenge on the vigilantes, while another group prepares to go into action.