During the conflict between the Dragons of Heaven and the Dragons of Earth, the dream-seer Princess Hinoto foresees the end of humanity. The central figure, 15-year-old Kamui Shirou, must choose whether to ally with the Dragons of Earth to destroy civilization in order to protect the planet, or with the Dragons of Heaven to save mankind. Heeding his mother's final wish, Kamui returns to Tokyo after six years of self-imposed exile. There, he tries to steal the Sacred Sword from the temple guarded by Kyougo Monou—the father of his childhood friends, Fuuma and Kotori. However, after Kamui's attempt fails, a mysterious individual manages to obtain the sword instead. Convinced that Kamui is the man from her prophecy, Hinoto dispatches the Dragons of Heaven to recruit him to their cause. Although Kamui initially rejects his destiny, the relentless attacks by the Dragons of Earth against those he cares for force him to decide whether the lives of his friends should take precedence over the fate of the Earth, and ultimately choose a side.