In AD 2058, on Clayad, the third planet of the Ypserlon system, located 43 light years from Earth, aliens suddenly raid the planet. The residents of Clayad must flee. Amid the chaos of the escape, children are separated from their parents and board the training spaceship Janous. After many sacrifices, they manage to reach the fourth planet, Belwick. However, since Belwick is already at war, the 13 children continue their journey toward Earth on their own.