Mayoko Okino is a supporting character in the manga series ZONE-00. She is a human girl who becomes involved in the supernatural events surrounding the main characters. Mayoko is known for her cheerful and kind-hearted personality, providing emotional support to those around her. Despite lacking supernatural abilities, her courage and determination help her navigate a world filled with demons, exorcists, and mysterious happenings. Her role in the series often brings a sense of normalcy and warmth to an otherwise dark and action-packed storyline.