Their love was forbidden... The angels and devils have been rivals for centuries, neither clan able to tolerate the other. Evangelina Leclair is an angel in the Land of Heavenly Dreams. One day, her parents enroll her in Horizon High, a school in the human world. They assign her the task of assassinating Diome Lenoir, a devil who is studying there. As a pacifist, she decides to protect Diome in secret instead of obeying her parents. A string of coincidences brings her and Diome closer, and they develop a mutual infatuation and become a couple. ​​​​​​​Their forbidden love is challenged again and again as dangers threaten to destroy their relationship. With each other by their side, Evangelina and Diome discover the beauty and brutality of the world, learning to embrace the miracles that blossom from their epic romance.