Sousou, a self-absorbed and callous young man craving excitement in his mundane life, crosses paths with Hanami, a high school girl with a strong sense of justice and a peculiar 3-meter radius of influence. Their worlds collide when individuals worldwide gather for the impending doom of humanity. Entrusted as the chosen representatives by the enigmatic 'concierge' aboard the 'Ark,' they learn of a plan to reset civilization. Now faced with the daunting task of selecting the future of mankind amongst themselves, a harrowing tale of survival and calamity unfolds.