Atoru, an Aztec girl born in Mexico, was orphaned while living in Texas with her family. In desperation, she prayed to the Aztec god Quetzalcoatl, summoning a Yoi—a supernatural entity—that took the form of a horse capable of transforming into a dragon. She named this creature Yukiwa. Inspired by tales of Japan from stranded samurai, she journeyed there seeking peace and acceptance.

Arriving in Edo-era Japan, Atoru faced harsh discrimination for her foreign origins and bronze skin. To evade persecution, she artificially lightened her skin with makeup to pass as Japanese. She and Yukiwa performed together in a circus until her true identity was exposed, inciting public revulsion. Subsequently, the character Genbatsu arranged her placement as a ward of geishas in the red light district, though she did not train as a geisha.

Atoru uniquely perceives Kumoshichi, a Yoi manifestation created by Yukiatsu that resembles a human. She alone—alongside Yukiatsu—recognizes Kumoshichi’s supernatural essence, an ability no other characters share. During a critical incident where Yukiwa ran wild, Kumoshichi merged with the creature to calm it, transforming Yukiwa into a talking horse who remained with Atoru.

In the OVA *Ayashi Divine Comedy*, set six months after the main series, Atoru participates in events involving a Stable Time Loop. She and fellow Ayashi members implicitly aided the young Yukiatsu in returning from the Other World to the human realm in the past, crucially resolving the overarching conflict.

Her arc explores themes of cultural displacement, resilience against prejudice, and forging bonds amid societal exclusion. Her interactions with Yukiatsu evolve into a relationship defined by mutual understanding and shared outsider experiences, extending beyond superficial attraction.