Uma-tan holds the title of Eto-Shin of the Horse, one of twelve celestial guardians representing the Chinese zodiac. Her demeanor combines unwavering focus with intense seriousness, often leading her to interpret events pessimistically and accept disproportionate responsibility for setbacks. Tasked with presiding over sacred rituals in the Eto World, she safeguards its ancient traditions with meticulous dedication.

Her striking appearance features equine ears, a cascading ponytail extending into Rapunzel-like lengths, and a prominent tail. She wields a staff as both weapon and ceremonial emblem. Outside her formal duties, she channels her creativity into writing and publishing manga—an endeavor that contrasts sharply with her otherwise rigid, duty-bound existence.