The Mutou family leads a peaceful life: Kouichirou works at a construction site and his wife Mari is returning from an overseas trip. Their daughter Ayumu has just finished her track practice while their son Gou is playing video games at home. However, life as they know it is flipped upside down when a calamitous earthquake strikes the entire Japanese archipelago—obliterating the face of the country in an instant. With society crumbling around them and their nation gradually sinking into the ocean, the Mutou family must band together to survive the catastrophe. Treading the near-apocalyptic setting, they struggle not only to stay alive, but also to learn the difficulty of coping with loss.
Hinako is a surf-loving college student who has just moved to a small seaside town. When a sudden fire breaks out at her apartment building, she is rescued by Minato, a handsome firefighter, and the two soon fall in love. Just as they become inseparable, Minato loses his life in an accident at sea. Hinako is so distraught that she can no longer even look at the ocean, but one day she sings a song that reminds her of their time together, and Minato appears in the water. From then on, she can summon him in any watery surface as soon as she sings their song, but can the two really remain together forever? And what is the real reason for Minato's sudden reappearance?
With its armies sweeping across the continent, the Empire seems unstoppable. After securing victory over the remnants of the Republic's army, the Empire's ultimate victory is finally within reach. However, dark clouds are gathering in the East. The communist-led Russy Federation is mustering troops on its western border, preparing to enter the war. Supported by a detachment of Allied volunteer magicians—among whom is Mary Sioux, the daughter of a soldier killed by Tanya—the Federation is determined to spread the communist creed and bring the Empire to its knees.
Meanwhile, Tanya and her battalion return to the imperial capital from the southern front. Upon their arrival, they are tasked with investigating troop movements on the border with the Federation. Any escalation of violence at this point may lead to new conflicts, plunging the world into a global war.
Will the Empire eventually emerge victorious from its struggle, or will it crumble in the face radically different ideologies?
