This world is sick, and you and I are both pitiful creatures, living and dying over and over again in this world. People have always remembered the root of it all, never daring to forget: On January 1, 2045, a blizzard swept across the world, and temperatures fell to an all-time low. The United Nations intervened, barely keeping human society in order. On March 2, countless ghosts emerged from underground and attacked humanity, which suffered one defeat after another. In the end, the United Nations launched the Ark Plan, establishing a number of arks in various countries and initiating the Ark Alliance Plan. Humanity huddled together in these shelters, hoping to survive.
