Panny is a baby panda residing with his father, Papa Panda, at Mimiko's bamboo grove home. Initially discovered sleeping on Mimiko's doorstep, he forms an instant bond with her, establishing an unconventional family unit. He and Papa Panda previously escaped a local zoo before finding refuge with Mimiko.

Panny displays a playful and curious nature. He frequently disobeys instructions, such as secretly following Mimiko to school despite orders to remain home, triggering a chaotic chase by schoolchildren—a testament to his persistent attachment to her. His outdoor adventures sometimes lead to trouble, including rolling down a hill and becoming separated from the family. This results in a perilous situation where he floats toward a floodgate on driftwood, requiring rescue by Mimiko and Papa Panda.

In the sequel *Rainy Day Circus*, Panny encounters a lost baby tiger named Tiny eating his food. After initial fright, he befriends Tiny, demonstrating adaptability and trust. He later follows Tiny to a circus, where his imitation of Tiny’s ball-balancing trick unintentionally provokes a chase by circus performers. His playful curiosity directly contributes to the climax involving a runaway circus train, though Papa Panda performs the heroic act of stopping it.

Panny remains consistently youthful and dependent across both films. His actions stem from innocent curiosity and a desire for fun rather than deliberate mischief. He relies on Mimiko and Papa Panda for guidance and protection during crises like the floodgate incident and circus train emergency. Within the family dynamic, he serves as a beloved child figure—often requiring rescue but fueling shared adventures through spontaneous behavior.