Houzaburo Ogasawara serves as the twenty-year-old leader of the Ayashi group within the Bansha Aratamesho, coordinating efforts to combat dangerous supernatural entities called Yōi. His position demands significant responsibility in directing the team against these threats.

Simultaneously, he operates as a scholar specializing in rangaku, the Edo-period study of Western sciences and knowledge. This expertise offers valuable insight into foreign methodologies and technologies, informing the Ayashi's strategies against otherworldly dangers.

His role places him at the intersection of supernatural operations and governmental politics, creating ongoing tension between his duties to the Ayashi and his involvement in the shogunate's intricate political schemes. This duality forces him to navigate competing demands and loyalties.

Within the Bansha Aratamesho's structure, he reports directly to financial magistrate Atobe Yoshisuke—a political adversary to South Edo Magistrate Torii Yōzō. This reporting line underscores his embedded position within the era's complex bureaucratic and power dynamics.