Chiharu belongs to an extraterrestrial species classified as a "super human," marked by distinct physiological features including magenta skin, elongated ears, and antennae, identifying her as a humanoid alien. She displays an energetic and expressive personality, frequently reacting with exaggerated outbursts like a loud "Eeehhhhh?!" when surprised or alarmed. In her friendship with the cyborg Makina, Chiharu often acts as the overtly troublesome counterpart, though their dynamic consistently leads them to jointly escalate situations during adventures.

While on a recreational drive along the interplanetary Milky Highway, Chiharu actively dodges a pursuing police drone alongside Makina, shouting a panicked "Eeehhhhh?!" when the drone deploys a weapon. She joins Makina in taunting the drone after its attacks fail, revealing a mix of impulsive daring and camaraderie. The chase concludes with her arrest alongside Makina for traffic violations, a direct result of Makina's reckless driving decisions during the pursuit. This incident leads to legal consequences requiring Chiharu and Makina to perform community service cleaning duties aboard the Milky Subway, an interplanetary transit system. This assignment forms the narrative foundation for their subsequent adventures.