Hana is an ordinary high school student who feels discontented with her everyday existence. One day, she experiences a vivid dream where she encounters a ten-year-old girl from the Sengoku Era. This girl endures hardship and adversity in her time, leading to a deep bond of sisterhood between them. Upon waking, Hana is apprehended by a government special agency and faces intense examination regarding her dream. They mention the Akashic Record, a mystical archive that tracks the destinies of all people, revealing that the future record of humanity will vanish within a month.