The grotesque Millennium Earl is an enemy of all of humanity. His greatest weapons are vile machines known as "Akuma," whose creation is made possible by the human emotions of despair and longing. Those who can purge Akuma from the world are known as Exorcists. One such Exorcist is a girl named Robin, whose odd appearance mismatches her sheepish personality. Long ago, she lost someone important to her, which now serves as her driving motivation.

After washing up on the shores of Osaka, Robin comes across a girl named Lenalee, who yearns for the lover she had lost at sea years ago. These feelings of longing catch the attention of the Millennium Earl, who has likely found his next victim...