Yozo Torii occupies the office of South Edo Magistrate and rules as lord of the Kai domain. He is a dedicated proponent of Chief Elder Mizuno Tadakuni's Tenpō Reforms and is instrumental in enacting these political and economic measures throughout the Tenpō era. As a high-ranking official, his responsibilities require him to navigate and enforce these policies with precision.

He extends an offer of recognition and legitimacy to the supernatural investigation unit Bansha Aratamesho, contingent on their recruitment of a drifter named Ryūdō Yukiatsu. His governance is marked by strategic and severe decisions, including the authorization of a human sacrifice—a person known as Atl—to placate a rampaging serpent-like Youi.

His unwavering political stance draws hostility from opposition forces, such as mountain tribesmen who carry out an unsuccessful assassination attempt. Torii’s duties also involve direct oversight of public works, exemplified by his supervision of construction at Inba Marsh. When a Youi threatens the site, his rival Atobe Yoshisuke capitalizes on the crisis, aiming to orchestrate Torii’s disgrace by commanding the Ayashi to withhold assistance.