The Shin Yogo Empire is in the midst of a catastrophic drought which threatens to bring about famine. The Star Readers, tasked with preventing this disaster, must develop a plan. According to legends, the first emperor and his eight warriors vanquished a water demon to spare the land from a similar calamity. Presently, the water demon, who resides in the emperor's son, Prince Chagum, may be their sole hope for salvation. Unfortunately, to rescue the empire, the emperor instructs the sacrifice of Chagum. Amidst the chaos, Balsa, an experienced mercenary, enters Shin Yogo with a quest for closure. Upon foiling a murder plot on Chagum's life, the prince's mother beseeches Balsa to safeguard him from the emperor's hunters and his own father. Motivated by a duty-bound obligation, Balsa agrees to watch over the young prince. Seirei no Moribito chronicles Balsa's struggle to protect Chagum from harm, all while discovering the wonders of life, the significance of kinship, and the unexpected bonds that can arise between strangers.