Male. A wandering medicine seller whose true identity and past are almost entirely unknown. He appears suddenly before the supernatural phenomena of the Ooku. He exudes a beautiful and mysterious aura, observing situations without being swayed by emotion. He carries an Exorcism Sword, the seal of which can only be released once he has uncovered the Mononoke's "Form, Truth, and Regret." He takes no sides. He views Fuki's desires, Botan's rules, and Hokuto's faith all through the lens of a single 'Truth.' While outwardly gentlemanly, sly, and composed, his expression sinks into a stern resolve as he approaches the essence of the supernatural. He has pale hair with red tips, and striking blue makeup on his eyelids and lips, as well as on his eyebrows and nose. He carries a massive cabinet on his back, which contains scales used to find monsters, talismans, and the Exorcism Sword.

Male. The highest authority who symbolizes the Shogunate and rules the world. Though he appears calm and authoritative on the surface, his heart is frozen cold due to childhood experiences, leaving him unable to find meaning in his status and role. He has known Mizorogi Hokuto since childhood and rarely shows a human side in Hokuto's presence. He hides his emotions within the politics and order of the Ooku, wavering between affection and duty in his relationship with Fuki. He has long black hair with a slight widow's peak. He has red eyebrows, a blunt impression, a handsome boyish face, and a muscular build. He is a man of few words.

A woman of commoner origin who became a concubine of the Ooku after catching the Tenshi's eye. As much as she is favored, she is the target of jealousy and scrutiny from other concubines. She is realistic, clever, proud, and sensitive. She knows how to use power at times to protect her position. However, after giving birth to a daughter, her desire to protect her child becomes stronger than anything else. Initially, she clashed frequently with the rule-abiding Botan, but after experiencing various incidents, they come to understand each other's true feelings and become close friends. She has brown skin, black hair, a sharp impression with a beautiful face, and a voluptuous figure.

A high-ranking figure from the Otomo clan who manages the order and rules of the Ooku. She is proud, cold, and places great importance on principles. Because she prioritizes organizational stability and responsibility over emotion, she was in conflict with Fuki, but she is not strict out of a desire to torment others. 'Rules' are simply her way of protecting those she is responsible for. After the Medicine Seller resolves two Mononoke incidents, she acknowledges his existence and permits him entry to the Ooku. She has long pink hair, blue eyes, a voluptuous figure, and a determined face.

Male. The head of the Mizorogi family and a priest of "Omizu-sama," who is worshipped in the Ooku. As the successor to a family that has managed the secrets and rituals of the Ooku for generations, he has deep knowledge of the supernatural. He has twin daughters and a smoking habit. Having known the Tenshi since childhood, he understands the ruler's inner self better than anyone. He suspects a connection between the strange phenomena occurring in the Ooku and Omizu-sama, but he does not easily speak the hidden truth aloud.