Kame and Crane are two young girls who survive a catastrophic event, found amidst the rubble and the dead. They grow up in a children's home with no memory of that fateful day, the details of which remain a complete blank in their minds. The story follows their lives as they navigate an ordinary existence in a world that has been irrevocably changed by the disaster they cannot recall. The narrative centers on these two miraculous children, exploring how the trauma of an unremembered past shapes their present and the mystery of what exactly happened on the day that altered their world forever.

The main characters are Kame and Crane, two girls whose very survival is considered miraculous. They live in a Children's Home, a setting that serves as the primary backdrop for their upbringing and the gradual unfolding of their shared history. The central conflict revolves around the mystery of that day, the event that left them orphaned and without memories. The plot is driven by their quest to understand their own past and the nature of the catastrophe they escaped, as the world around them has moved on from an incident they are unable to even acknowledge.

The manga is structured around the gradual revelation of the past. The story begins in the aftermath, focusing on the girls' life in the orphanage and the gap in their memories. As they grow, the narrative likely shifts to incorporate flashbacks or discoveries that piece together the events of the disaster. The complete story is told in a concise format, spanning two volumes that cover the initial setup, the slow unearthing of buried truths, and the ultimate resolution of the mystery of that day and its impact on the protagonists.