Shapojii manifests as an elderly demon permanently bound to the physical form of a sentient hat, almost always perched atop Enma's head. His extensive knowledge of the underworld and demonic entities makes him a critical advisor; he alerts the group to nearby demonic presences and suggests strategies for confronting escaped demons. Advanced age causes him to frequently lapse into deep sleep, limiting direct involvement in most situations, though his presence remains vital for guidance and information.

The manga adaptation portrays a significantly younger and more dynamic Shapojii. In this version, he gains the ability to alter his shape and appearance beyond the static hat form. His personality shifts toward greater aggression and proactive participation in missions, adopting a more visible and combative role alongside the main characters compared to his relatively passive OVA counterpart.

He appears consistently across narrative iterations, including the original OVA series and its manga source material.