"Moribito - Guardian of the Spirit" is a 26-episode anime series based on the first novel of Nahoko Uehashi's "Moribito" series. The story is set in a fictional world inspired by ancient Asian cultures and revolves around Balsa, a skilled warrior and bodyguard who wanders the land seeking redemption for past sins. Her life takes a dramatic turn when she saves Prince Chagum, the second son of the Emperor of New Yogo, from a mysterious assassination attempt. Chagum is revealed to be the host of a water spirit, a fact that places him in grave danger. The Emperor, believing the spirit will bring drought and ruin to the kingdom, orders Chagum's death, forcing Balsa to take him under her protection.

As Balsa and Chagum flee the capital, they uncover the truth behind the water spirit and its connection to an ancient legend. The spirit inside Chagum is tied to the survival of the land, and its presence is not a curse but a necessity for the balance of nature. The series explores their journey as they evade the Emperor's forces, seek allies, and unravel the mysteries surrounding the spirit. Along the way, Balsa's combat skills and unwavering resolve are tested, while Chagum grows from a sheltered prince into a courageous young man determined to fulfill his destiny.

The narrative delves into themes of sacrifice, duty, and the interconnectedness of humanity and nature. Supporting characters, such as Tanda, a healer and Balsa's childhood friend, and Torogai, a wise and eccentric magic weaver, play crucial roles in aiding the protagonists. The series balances action, emotional depth, and world-building, presenting a rich tapestry of political intrigue, spiritual lore, and personal growth. The story concludes with a resolution that ties together the fates of the characters and the spirit, emphasizing the importance of harmony between the natural and human worlds.