Panpaka hails from Shizuoka Prefecture, Japan, belonging to the Pants family, a lineage historically entrusted with securing the world's most sacred underwear. His family charged him with this mission, prompting global adventures with his companion Punyan, a purple cat who assists despite communicating solely by uttering his own name. He is typically depicted wearing only his signature white briefs, a design originating from an earlier character named Taisuke featured in pre-series one-minute shorts.

During a family vacation intended for Hawaii, he became separated from his relatives at the airport and accidentally journeyed to the Bananan Kingdom, a jungle nation. Mistaken by its ruler for the prophesied "Legendary Pants Hero," he accepted the quest to retrieve their sacred pants. This required confronting the Alligator King, who had seized all bananas, forcing citizens to subsist solely on ice cream. On this journey, he allied with three animal companions: Wanpoko the dog, Terry the monkey, and Orson the crane. Their tendency for mooning created comedic friction with his dedicated underwear-centric focus.

His personality features enthusiastic dedication to finding rare underwear, often pursuing daring adventures regardless of risk. This drive persists even though successful acquisitions of special pants frequently culminate in disappointment or surreal outcomes. He maintains a largely indifferent attitude towards Boark, an eye-patch-wearing "Pants Hunter" who considers him a rival. His relationship with Punyan is central, relying on the cat's intelligence to navigate dangers, though Punyan's feline nature sometimes leads to distractions like responding to cat food. His family, particularly his grandfather who initially passed down the pants-finding mission, occasionally supports his endeavors.