Hozaburo Ogasawara commands the Ayashi as their 20-year-old leader within Edo-era Japan's covert Bansha Aratamesho, an organization dedicated to repelling supernatural Yōi threats. His scholarly expertise in rangaku reflects a deep intellectual engagement with Western knowledge and cultures. This role demands he coordinate Ayashi operations against Yōi while navigating intricate governmental schemes and political pressures from the shogunate. Balancing the Ayashi's mission against bureaucratic manipulations frequently places him in perilous situations.

He reports directly to Yoshisuke Atobe, biological brother of Chief Elder Mizuno Tadakuni, anchoring him within the era’s power structures. As the Ayashi regroup six months after major events to confront a new menace and conspiracy, Hozaburo continues steering the team through escalating dangers. His leadership oversees diverse members: the cross-dressing priest Genbatsu Edo, spear-wielder Abi, young fan-wielder Saizo, and drifter Ryūdō Yukiatsu, who wields Ayagami power. His documented responsibilities center exclusively on Ayashi leadership and political navigation.