"Ainu Teisōnin・ Kira Heijirō ～Ainu Nenoan Ainu～" is a historical drama set in the late 19th century, during the Meiji era in Japan. The story centers on Kira Heijirō, a half-Ainu, half-Japanese man who serves as a government-appointed magistrate in Hokkaido. Tasked with mediating between the indigenous Ainu people and the encroaching Japanese settlers, Heijirō navigates the complexities of cultural conflict, identity, and justice. His dual heritage places him in a unique position, as he is both an outsider and an insider to both communities, allowing him to understand and empathize with their struggles while facing mistrust from both sides.

The narrative explores the tensions arising from the Japanese government's efforts to assimilate the Ainu people and exploit Hokkaido's resources. Heijirō's role as a mediator often puts him at odds with corrupt officials, greedy settlers, and even some Ainu leaders who resist change. Throughout the series, he strives to protect the rights and traditions of the Ainu while grappling with his own sense of belonging and the moral dilemmas of his position. The story delves into themes of cultural preservation, colonialism, and the personal cost of standing between two worlds.

Key characters include Heijirō's Ainu mentor, who teaches him about Ainu customs and spirituality, and a Japanese settler family whose interactions with Heijirō highlight the broader societal conflicts. The series also features a diverse cast of Ainu individuals, each representing different perspectives on the changes brought by Japanese colonization. The plot unfolds through a series of episodic cases and conflicts, with Heijirō working to resolve disputes, uncover injustices, and uphold his principles in a rapidly changing world. The narrative is grounded in historical context, offering a nuanced portrayal of the Ainu people's resilience and the challenges they faced during this transformative period.