Chapeau Jii is a sentient hat demon serving on the Demon Patrol, tasked with capturing escaped youkai. He acts as an information broker and guide, wielding encyclopedic knowledge of supernatural entities to provide exposition on threats and mission objectives. His abilities are limited to levitation, rendering him a non-combatant support character.

His core role remains consistent across adaptations: accompanying the demon prince Enma to offer tactical guidance and situational analysis. He features as a running gag involving voyeuristic behavior, such as attempting to view female characters in compromising situations or taking advantage of unconscious characters during bath scenes, aligning with the series' ecchi themes.

In *Ghastly Prince Enma Burning Up* (2011), his hat form displays expressive facial changes during comedic or risqué moments. A notable visual gag involves him "boning" Enpi's hat, implying suggestive interaction through blurred imagery. He adheres to Blue-and-Orange Morality, casually referencing pragmatic solutions like soul extraction from humans, reflecting his demonic perspective.

Manga iterations depict a marginally more active version, sometimes using shapeshifting abilities and showing greater initiative to assist the team beyond advisory roles. However, no significant character development or backstory expansion occurs in spin-offs like *Dororon Enpi-Chan* or in official movies or OVAs; his role remains strictly ancillary, focused on support and comic relief.