"Kunimatsu-sama No Otoridai" centers on Kunimatsu, a young man who unexpectedly inherits the title of "Otoridai," a prestigious and ancient role within his village. The Otoridai is tasked with maintaining the balance between the human world and the spirit realm, a duty that has been passed down through generations. Kunimatsu, initially reluctant and ill-prepared, must quickly adapt to his new responsibilities as supernatural threats begin to disrupt the village's peace.

The narrative unfolds as Kunimatsu learns to harness his latent spiritual abilities under the guidance of his mentor, an elderly priestess named Sayuri. Alongside Sayuri, Kunimatsu is aided by a group of villagers, each with their own unique skills and connections to the spirit world. Among them is Tsubaki, a skilled warrior with a mysterious past, and Haruto, a mischievous but loyal spirit who serves as Kunimatsu's companion and protector.

As Kunimatsu grows into his role, he faces increasingly dangerous challenges, including malevolent spirits, ancient curses, and rival factions seeking to exploit the village's spiritual energy. The story explores themes of duty, sacrifice, and the struggle to reconcile personal desires with communal responsibilities. Kunimatsu's journey is marked by moments of self-doubt and growth, as he gradually earns the trust and respect of both the villagers and the spirits he is sworn to protect.

The series balances episodic encounters with an overarching plot, revealing the history of the Otoridai and the deeper mysteries of the spirit realm. Key revelations about Kunimatsu's lineage and the true nature of his powers add layers of complexity to the narrative. The interplay between the human and spirit worlds is a central focus, with the series delving into the cultural and spiritual traditions that bind them together.

Through its exploration of folklore and mythology, "Kunimatsu-sama No Otoridai" presents a rich and immersive world, blending action, drama, and supernatural elements. The characters' relationships and personal struggles are interwoven with the larger conflict, creating a cohesive and engaging storyline. The series ultimately builds toward a climactic confrontation that tests Kunimatsu's resolve and the strength of the bonds he has forged.