A new breed of darkness has risen. The citizens of Rengoku live at the mercy of a mysterious and barbaric cult, whose ultimate goal can only be described as opening the very gates of Hell itself. Caught in the middle of the struggle and now determined to put a stop to it is Nobuyuki Honda, whose life is thrown for the wildest loop when he forms an ethereal bond called a Soul Embrace with the succubus Delilah. As they band together with Nobuyuki's friends and even the messengers of above, they pledge to push back against the evil and discover what the forces of the underworld have planned. But the cult is not alone, accompanied by the almighty archdemons that seem to have made Nobuyuki their prime target.