Fumetsu no Anata e opens with an Orb, known only as It, cast to Earth to be watched from afar. Able to take the form of whatever it reflects, It begins as a rock and then becomes moss as the temperature rises. For a long time, It remains motionless until a snowy day brings a wolf at death's door past its path. When It assumes the wolf's shape, it finally gains awareness of consciousness and begins to wander with no clear destination.
It soon encounters the wolf's master, a young boy who is waiting for his tribe to return from a paradise in the south said to be rich with fish and fruit. Lonely but hopeful, the boy still believes the people he cherishes have not forgotten him and that they will meet again one day. Drawn by curiosity and by the traces his tribe left behind, he decides to leave home with It and search for that paradise.
With a heavily injured body and no sight of his elder comrades, the boy's journey is uncertain from the start. Across many places and many eras, Fumetsu no Anata e follows an immortal being as it experiences humanity, meets all kinds of people, and carries their memories forward.