As the demons of Hell face defeat in their war against Heaven's angelic forces, they stand on the brink of annihilation. In a desperate move to reverse their fortunes, they dispatch Akutsu Masatora to Earth's mortal realm to salvage their realm from the angels. Masquerading as a high school student, Akutsu's mission is to find a leader capable of guiding the demons to triumph.

Akutsu's search is brief; he finds Lily Amane, a remarkable transfer student who appears to be an ideal recruit for his cause. However, fate plays a cruel trick: Lily is one of the angels Akutsu is destined to battle. His recruitment efforts could become the greatest folly in this dire war. To complicate matters further, Akutsu risks falling for the very enemy he should defeat.