When savage monster girls suddenly began to appear, humanity stood no chance. One by one, people were drained of their life force and killed. Amid this hopeless crisis, the protagonist—having wandered deep into the mountains in search of a place safe from the monsters—loses his footing and falls from a cliff. When he comes to, he finds an unfamiliar sword in his hand. “Use the Spirit Sword… and save the world.” A voice echoes from somewhere unseen. Could someone with such a frail body really become a hero…? Caught between doubt and belief, he takes up the Spirit Sword and faces the monsters. But reality is harsh—he is defeated in an instant. His life force is relentlessly drained, and after a series of cruel reversals, he dies… —Or so it should have been. Huh…? I definitely died… didn’t I? I’m alive again…? And somehow… I feel stronger? Will the protagonist truly be able to save the world, as the prophecy foretold?