Papa, also known as Papa Panda, is a large male panda who becomes a central member of the household in the animated short Panda! Go, Panda!: Rainy Day Circus. His background begins in the earlier film of the series, in which he and his son Panny escape from a local zoo and make their way into the life of a young girl named Mimiko, who lives alone in a house near a bamboo grove. When Papa offers to become Mimiko's father, the three form an unconventional family, with Mimiko taking on the role of mother to Panny. By the time of Rainy Day Circus, this arrangement is fully established, and Papa lives as a permanent part of the household while still spending part of his time at the zoo.

In personality, Papa is warm, friendly, and good-natured. He greets people politely and often says pleasant things about them, and he takes obvious delight in simple pleasures, particularly bamboo groves, which he frequently praises and names as his favorite thing. He is playful and good-humored, readily joining in his family's antics and accepting the human customs that Mimiko teaches him. When Mimiko explains that a father should wear a hat, go to work, and read the newspaper, he obliges cheerfully, even when the idea of a workplace puzzles him. His signature trick is the handstand, which reflects his playful side.

Papa's motivations center on caring for his family and protecting those around him. As the father figure of the group, he is guided by a desire to keep his son Panny and adopted daughter Mimiko safe and happy, and he responds to trouble with calm, decisive action. He also shows genuine concern for others in need, joining wholeheartedly in rescue efforts for strangers and animals alike.

In the story of Rainy Day Circus, Papa plays a central part in the household's adventure. When a circus ringmaster and an accomplice break into the home looking for a missing tiger cub, Papa helps scare them off, and the family soon befriends the cub, named Tiny, after the tiger is discovered hiding in the house. Later, when heavy rain floods the town and leaves the circus train stranded with all its animals aboard, Papa joins Mimiko and Panny in setting out to help. His strength proves decisive at the climax: when the freed animals accidentally cause the train to roll out of control toward the mayor's house, Papa stops the train, saving the day and turning the family into local heroes. In the film's closing scene, the family celebrates by marching together at home, with Papa playing a tuba.

His key relationships shape the story. With Panny, his son, he is affectionate and protective, and he follows the energetic cub's escapades with patience. With Mimiko, he is a devoted and gentle adopted father, fully embracing the role she has chosen for him and supporting her leadership of their small family. His bond with Tiny is welcoming and friendly, and he interacts warmly with the circus people once the misunderstanding about the break-in is resolved.

In terms of development, Papa grows from an escaped zoo animal into a dependable member of an unusual family. Over the course of the two films, he commits himself to the domestic life Mimiko offers, and in Rainy Day Circus his role expands from household father to community rescuer. His willingness to embrace his new family and take on responsibility shows a steady character who thrives on caring for others.

Papa's most notable ability is his remarkable physical strength, which he uses to protect his family and assist others. In the earlier film he closes a heavy floodgate by hand to save Mimiko and Panny from dangerous waters, and in this sequel he brings a runaway train to a halt. He also has a talent for handstands, and his ability to speak and understand humans allows him to take part fully in family and community life.