Rinne Natsume was an ordinary high school girl living her life thinking nothing of it, until she discovered the secret behind her existence. A few months ago, she was attacked by a satanic cult and lost her father. At that moment, the power of the “God of Death” within her awakened, and she sought immediate revenge against her attackers. In the end, the momentary peace does not last long, and she finds herself trapped. Akuto, the head of the Order’s branch, has unleashed all his resentment against Rinne for the wounds inflicted by her father. Now, the sacred mating ritual between the Devil and Death is about to begin. Then the wandering exorcists Setsuna Shindou and Yuuka Shindou appear. But despite putting up a good resistance, they find themselves surrounded by a large number of cultists… What awaits them beyond this desperate situation?