Mukitetsu is a male Cocotama spirit born from a horizontal bar. He takes the form of a pale blue canine with turquoise ears, oversized paws and feet, small dark blue eyes, and a signature oval-shaped purple nose. His diaper prominently displays a gold barbell marking.

Personality-wise, Mukitetsu remains quiet and reserved, primarily whispering his thoughts to Tokumaru. Despite his silent nature, he wields immense physical strength, showcased by his ability to easily hurl humans from playgrounds. This power holds a specific limitation: it can be overpowered only when faced with the combined force of Kokoro Cocotamas.

A defining quirk is his unwavering commitment to a scheduled naptime, serving as a consistent running gag.