"Moribito" is a manga series adapted from the first novel of the "Guardian" series by Nahoko Uehashi. The story centers on Balsa, a skilled warrior and bodyguard who roams the land seeking redemption for a past tragedy. 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 as the spirit is believed to bring drought and ruin to the land. The Emperor, fearing the prophecy, orders Chagum's death, forcing Balsa to take on the role of his protector.

Balsa and Chagum flee the capital, pursued by the Emperor's elite hunters and supernatural forces tied to the water spirit. As they journey together, Balsa trains Chagum in survival skills while uncovering the truth about the spirit and its connection to the kingdom's ancient myths. The narrative explores themes of duty, sacrifice, and the clash between tradition and progress. Supporting characters, such as Tanda, a healer and Balsa's childhood friend, and Torogai, a wise and eccentric magic weaver, provide crucial assistance in their quest.

The story delves into the political and spiritual complexities of New Yogo, revealing how the kingdom's history and beliefs shape its present. The water spirit, initially seen as a curse, is gradually understood as a vital force tied to the land's survival. Chagum's transformation from a sheltered prince to a resilient young man mirrors the broader struggle to reconcile humanity with nature and tradition with change. The manga balances action, mystery, and emotional depth, offering a rich exploration of its characters and world.