"Children Who Chase Lost Voices" is a fantasy adventure anime film directed by Makoto Shinkai. The narrative centers on Asuna Watase, a young girl living in a rural town, who spends her days listening to a mysterious radio broadcast from a crystal radio her late father left her. One day, while exploring the mountains near her home, Asuna encounters a strange creature and is saved by a boy named Shun, who claims to be from Agartha, a mythical underground world. Shun possesses a magical artifact called the "clavis," which holds the key to Agartha.

After Shun mysteriously disappears, Asuna meets his older brother, Shin, who reveals that Agartha is a realm where the dead can be resurrected. Together with her teacher, Mr. Morisaki, who has his own reasons for seeking Agartha, Asuna embarks on a journey to the underground world. Along the way, they face numerous challenges, including hostile guardians, treacherous terrain, and the moral dilemmas surrounding the pursuit of eternal life.

The story explores themes of loss, grief, and the human desire to overcome mortality. Asuna’s journey is both physical and emotional, as she grapples with her father’s death and her growing understanding of the consequences of tampering with life and death. The film’s narrative is driven by its richly detailed world-building, blending elements of mythology and science fiction, and its exploration of the characters’ motivations and relationships. The central conflict revolves around the ethical implications of Agartha’s power and the sacrifices required to achieve one’s deepest desires.