Aki Amano is a reporter investigating illicit practices—including sexual assaults and drug testing—at a Western-style hospital directed by her stepfather. She displays a confident, assertive demeanor, frequently seen smoking cigarettes while confronting hospital staff like nurse Midori about criminal operations. Her motivation for journalism stems from a formative youth event: discovering her mother's infidelity, an experience that led her to derive sexual satisfaction from uncovering secrets, fueling both her career and personal compulsions like surveilling her mother afterward.

She encounters Takumi, a patient with the unique ability to perceive past events ("deep voices") and enter others' consciousness during sleep. Recognizing his value for her investigation, particularly into secrets hidden in the hospital basement, she persuades him to assist her. Her methods prove effective, and they collaborate closely to expose the institution's darker activities, extending beyond medical misconduct to possible disappearances linked to an on-site crematorium.

Her investigation intensifies as she pursues leads concerning a person named Shiori, provoking a violent reaction from Midori. Due to insufficient caution during her inquiries, she is eventually captured by the director, complicating her efforts to expose the truth. Physically, she is characterized by pink hair and petrol-colored eyes.