Isao splits from the protagonist's subconscious following a meteorite impact that fractures the main character into three distinct beings. He manifests physically as a strange, dog-like creature. His primary function is to guide the protagonist through the conflict arising from this event. Isao exists alongside the protagonist's evil counterpart, the Rival, who also gained supernatural abilities from the impact. He assists the protagonist in navigating the challenges presented by the Rival across the narrative. His presence is intrinsically tied to the core premise of the split consciousness and the resulting struggle for reintegration or resolution.