Fifty years after the supercomputer Noah destroyed human civilization, the protagonist Hinata lives quietly with foster sister Sasha and foster father Gib on desert islands—until a mysterious army attacks. Hinata and Sasha escape; Gib is taken. Sasha reveals the truth: Hinata, Gib, and others are "Hot Seeds"—survivors sealed in hibernation to preserve civilization and awaken to rebuild it. Sasha herself is an android assigned to protect them. The villains need Gib because he helped design the Black Mole, an indestructible mobile fortress built to fight Noah. Hinata must get Gib back before they can use it.