Rinna, a central character in *Panyo Panyo Di Gi Charat* and later a minor presence in *Digi Charat Nyo*, operates a beloved cake shop famous for its delicious offerings. Despite the shop's irregular hours stemming from her tendency to fall asleep unexpectedly, her exceptional baking skills earn her cakes the reputation of the planet's best. She passionately believes the essential ingredient is love and the anticipation of customers' happy faces, calling this the "baking powder of the heart."

Polite to everyone she meets, Rinna typically ends her sentences with the verbal tic "-myu." Though often sleepy, she possesses the surprising ability to run at extraordinary speeds, though she avoids it due to personal dislike. After joining Dejiko's group in *Panyo Panyo Di Gi Charat*, she temporarily closes her shop to help spread happiness across the planet.

In *Digi Charat Nyo*, Rinna reappears as a supporting figure and childhood friend to Dejiko, Puchiko, and Mike. She also makes a continuity cameo in *Reiwa no Di Gi Charat*, where characters note her return after a long absence. Rinna's design features blue or green hair, brown eyes, and animal ears, consistent with her origins from the planet Di Gi Charat. Her background lacks extensive elaboration across media, with no significant development or alterations to her core traits documented.