Ayumu Gōriki is a 41-year-old physician operating his own medical clinic and serving as primary doctor for Hiroshi Odokawa, who suffers from insomnia and psychological trauma. Initially suggesting marriage to address Odokawa's loneliness, Gōriki later investigates his patient's background upon recognizing the severity of his condition. This leads him to contact Odokawa's childhood doctor and review medical records, revealing that a childhood accident at age four killed Odokawa's parents and caused visual agnosia, resulting in Odokawa perceiving humans as anthropomorphic animals.

Gōriki employs Miho Shirakawa as his clinic nurse. When medications vanish with evidence suggesting Shirakawa's involvement, he considers shutting down the clinic to shield her from police suspicion, deliberately avoiding authorities to prevent her implication.

Professionally, Gōriki hypothesizes that Odokawa's exceptional recognition ability stems from synesthesia. He bases this theory on Odokawa instantly identifying Eiji Kakihana from a poor-quality photograph and recalling detailed information about bar patrons forgotten by others. Gōriki's investigation into Odokawa's past confirms the visual agnosia diagnosis through medical documentation.