Ren is Rin's twin sister, distinguished by her black hair against Rin's brown. She and Rin survived the tragic accident that killed their parents and were subsequently rescued and adopted by Wooser, establishing him and Darth Wooser as their unconventional guardians.

Ren displays a more precocious and bubbly energy compared to her calmer sister. She lives contentedly with Rin, Wooser, and their eccentric housemates, embracing them as family. While actively sharing their daily lives and observing Wooser's antics, she typically takes a less direct role in managing him than Rin.

Her experiences include joining beach outings in swimwear and participating in extraordinary events, such as transforming into a magical girl alongside Rin to battle a giant Mecha-Wooser.

A significant moment occurs in Season 2, Episode 5: a dream sequence or flashback depicts Wooser saving infant Ren and Rin from a fire that claimed their parents' lives. This scene, coinciding with Ren murmuring "Mama... Papa..." in her sleep, hints at a deeper, potentially traumatic past, though it remains ambiguous whether this is factual memory or part of Wooser's delusions.