Atonyan serves as Dr. Ochanomizu's artificially intelligent robotic feline companion. This character boasts superpowers akin to Astro Boy, including flight and other robotic abilities. Atonyan exhibits a playful yet troublesome nature, frequently zooming into trouble through impulsive actions before ultimately aiding in resolving problems.

Within Team Astro, Atonyan partners with Astro Boy and Suzu, traversing the globe via the Mage portal system to confront environmental crises, scientific anomalies, and minor emergencies. Atonyan's capabilities prove valuable to the team despite occasional mishaps during missions. Interactions with Suzu feature regular, non-malicious squabbles, defining their friction-filled rapport.

The character retains the Japanese name Atonyan, distinct from its English localization as Astro Kitty. No significant evolution or expanded background occurs beyond this established core role. Atonyan consistently provides comedic moments and lighthearted adventure, lacking deeper narrative development or origin exploration.

Official media beyond the 2019-2020 television series—such as films, OVAs, or spin-offs—does not include this character. All confirmed appearances and narrative contributions belong exclusively to this single production.