Demon Masatora Akutsu arrives on Earth with orders to recruit charismatic humans and bolster the morale of Hell's troops against an angelic invasion. His first target is Lily Amane, who turns out to be an angel stationed on Earth to hunt demons. Lily defeats Akutsu and forces an enchanted collar on him that compels obedience, turning Hell's envoy into her reluctant servant as the war between Heaven and Hell rages on unseen around them.