Amane Oguro, a 29-year-old woman with long black hair often tied in a ponytail, tan skin, and blue eyes, operates Ooguro-ya, a beachside shop in Choshi. As niece to Miki Shiba—who temporarily managed both the shop and Villa Rosa Sasazuka—she employs Sadao Maou and his companions after their apartment renovations, permitting them to revamp Ooguro-ya for customer appeal. Her energetic and caring nature drives her to provide financial support and bonuses to her employees during hardships.

Amane's heritage identifies her as the daughter of Earth's "Understanding" (Binah), granting her status as a planetary guardian. This role links her distantly to Alas Ramus through their shared connection to Sephirotic manifestations across worlds. Governed by cosmic restrictions, she cannot reveal information beyond what her aunt Miki (embodying Earth's Da'at) discloses. Initially suspected by Maou and Emi Yusa's allies of destabilizing Ente Isla and the Demon World—prompting demon minister Camio's pursuit—Amane clarifies her neutrality during Malebranche conflicts, asserting benign intent.

Her capabilities include immunity to demonic powers, demonstrated when Camio's abilities fail against her. During a critical event, she supplies Maou with a demonic sword forged from his own horn, enabling his temporary devil-form resurgence on Earth without negative emotions. Ooguro-ya and its beach serve as a Bon season spiritual sanctuary for soul purification. A colossal energy surge from Maou and Emilia ruptures this equilibrium, stripping souls of human forms and triggering Amane's disappearance. Post-event, she dismisses the group with final bonuses, erases all traces of her existence—rendering the shop and beach unreachable and eradicating local memory of her. Amane then relocates to Villa Rosa Sasazuka after her father expels her from Ooguro-ya over these events.