In a world threatened by the imminent death of its sun, young Yama lives a relatively happy and peaceful life as the daughter of the chief of the village. But everything changes the day a sword of glass falls from the sky, as prophesied. Orland, the local warlord, comes to seize the weapon, but fails, and Yama's parents are killed. Yama escapes and survives with only one thought: to retrieve the sword of glass and avenge the death of her parents by killing Orland with it. Yama is also the key to the swords of glass prophecy, which provides humanity with one last chance to survive.