In war-torn Japan, young Mahito grapples with the sudden death of his mother. Struggling with grief, Mahito and his father move to a rural village to start anew. Their new home is filled with mystery and memories, particularly an enigmatic tower that piques Mahito's curiosity. As he navigates this unfamiliar environment, Mahito encounters a talking heron that leads him into a fantastical world. This realm is home to surreal creatures and cryptic forces, mixing elements of beauty and danger.

Throughout his journey, Mahito learns profound truths about life, death, and the nature of existence. As the line between reality and fantasy blurs, he must confront his deepest fears and reconcile with the pain of his past. Embarking on this quest offers him a chance at healing, while also posing existential questions that challenge his growing understanding of the world. The story builds to a poignant exploration of loss, resilience, and the enduring spirit of human connection.