The Mutou family enjoys a tranquil existence: Kouichirou is employed at a construction site, while his wife Mari returns from abroad. Their daughter Ayumu has just wrapped up track practice, and their son Gou is immersed in video games at home. Suddenly, everything changes when a devastating earthquake shatters the entire Japanese archipelago, instantly reshaping the nation. As society crumbles and the country begins to sink beneath the sea, the Mutou family must unite to survive. Their home, once a quiet sanctuary, now echoes with distant tremors. In this near-apocalyptic scenario, they fight not only for survival but also confront the painful reality of loss. They cling to each other, seeking hope amid chaos.