Eru Harune, the younger twin sister of Aira Harune and sibling to Itsuki Harune, lives in Yokohama, Japan. At five years old, she mirrors her twin Uru’s appearance: short red hair styled in side-tails—Eru’s tied on the right—and bright orange eyes. Their coordinated outfits reflect their personalities, with Eru frequently incorporating orange into her wardrobe, contrasting Uru’s yellow accents.

Cheerful and playful, the twins enthusiastically aid their older sister in hiding her Prism Star activities from their father. Though devoted to Aira, they sometimes feel overlooked when her responsibilities keep her away. During their birthday, Aira’s initial reluctance to celebrate with them drives the twins to the Dream Tree, where Kaname Amamiya consoles them. Aira later reconciles, vowing to cherish their bond, inspiring Eru and Uru to pursue becoming Pretty Top managers to support Prism Shows like their sister.

Eru’s name (える) means “get,” while her surname Harune (春音) signifies “sound of spring.” A later-season flashback reaffirms her enduring link to Aira’s path.

Their design, marked by vibrant hair and color-coded outfits, informed Non’s creation in *PriPara*. Though central to exploring family ties, their growth evolves subtly across the series—transitioning from Aira’s eager helpers to determined individuals with distinct dreams, all while maintaining their shared passion for Prism Shows.