Papuwa is the title character and central protagonist of the anime that bears his name. He is a small boy who wears a simple grass skirt and has short dark hair and dark eyes, giving him a youthful and wild appearance that matches his island home. His origins are rooted in the first Papuwa Island, where he was discovered as a young child washed up on the shore alongside his animal companion Chappy. He was found by Kamui the owl, who took him in and adopted him, and he has lived on the island ever since. Papuwa is also the only known heir to the red stone, known as the stone of hope, a position that places him at the center of the story's long-running conflict between the red stone of hope and the blue stone of desire.

In personality, Papuwa is cheerful, energetic, and thoroughly carefree. He approaches the world with a childlike simplicity, showing little interest in complicated matters and reacting to events with directness and enthusiasm. He is open and welcoming toward newcomers and tends to treat nearly everyone he meets as a friend, often without concern for whether they arrived as an enemy or an ally. This trusting and naive nature is part of what makes him so disarming to the various soldiers and intruders who come to the island, as their serious plans are regularly overturned by his playful and unpredictable behavior. At the same time, he is strong-willed and protective when his friends or his way of life are threatened, and his innocent demeanor hides a surprisingly fierce side.

Papuwa's motivations are simple and tied to his island life. He wants to enjoy each day, play with his friends, and keep the peace of the tropical home he shares with a collection of strange creatures. In the later story, he becomes especially concerned with the safety of Kotaro, a boy who washes ashore with no memory of his past. Because Kotaro's hidden power is dangerous if it awakens, Papuwa works alongside his household to keep Kotaro calm and to prevent him from remembering who he is, motivated by a genuine desire to protect his new friend from harm. He is also bound to the larger matter of the red stone, as the heir to its power and hope, which ties his personal happiness to the fate of the island and the people around him.

His role in the story is that of the heart of the island community. Papuwa House, where he lives, becomes the gathering point for the island's many odd residents and for visitors who wash ashore. He is the figure around whom the group forms, and his presence often turns potentially serious conflicts into chaotic and comedic situations. Longtime characters from his past, such as the giant owl Kamui who raised him and the visitor Shintaro who became entangled with the island in earlier events, remain connected to him through shared history, and he regards his lifelong companion Chappy as his closest partner. He also forms a deep bond with Liquid, a former elite soldier who stays on the island as the household's caretaker, and the two develop a quiet mutual respect despite their very different temperaments. With Kotaro, he builds one of the most important friendships of the later story, accepting the amnesiac boy without hesitation and helping him feel that he belongs.

Over the course of the narrative, Papuwa's circumstances change around him even as his core character remains stable. Four years after the events centered on the first island, he has relocated to a second Papuwa Island, where he continues his role as host to a new set of eccentric residents and visitors. His position as heir to the red stone grows more meaningful as the story moves toward a confrontation between the red and blue stones, and he is drawn into events that carry him and the island into other worlds. Through it all, he continues to act on instinct, guided by friendship and loyalty rather than strategy, and he consistently chooses to stand beside the people he cares about.

His most notable abilities are physical and instinctive rather than magical in nature. He possesses extraordinary strength that far exceeds what his small frame would suggest, making him a formidable opponent despite his youthful appearance. He also has a range of other unusual capabilities, such as the ability to breathe underwater for up to three hours, which suits his life on a tropical island. In combat, he uses unorthodox techniques that involve kicking local animals, such as porcupines and tadpoles, at his opponents, turning the ordinary wildlife around him into improvised projectiles. These abilities, combined with his quick reflexes and fearless attitude, make him surprisingly dangerous whenever a fight becomes necessary, even though he rarely seeks out conflict on his own.