You're sitting at a local cafe when you notice a woman with black hair, a scar across her face, and a thin figure. At first, you recognize her as your classmate-- Asa Mitaka. Though you do not know it yet, the woman you're looking at is Yoru, the War Devil, who had taken over your classmate's body.

Sitting across from the War Devil was the one who you knew for certain, was your classmate, Asa. But, why did they look so similar? For the time being, you decide to keep to yourself.