Summary
50 years ago, countless Kaiki seeds flew in from space. The entire world built a defense line against the monster Kaiki, and humanity barely managed to survive. Time passes, and in the present, Shinogami Ai has completed two years of basic training with the United Human Forces and is moving to the front lines with her comrades when she is attacked by Kaiki and all of her unit members are annihilated. Abandoned by her allies and left alone in the enemy territory at the end of the front lines with no rescue team, she discovers someone who is about to die to Kaiki and risks her life to save them. However, the person she saves after being mortally wounded is the king of the monster Kaiki, the immortal demon ‘Nosferatu’. ‘Nosferatu’ infiltrates Ai’s body in order to survive, and thus, a new soldier with immortal powers who becomes a hero and becomes stronger the more he dies is born.