Jim Hawkins is the main protagonist of the 1978 Japanese anime television series, which is an adaptation of the classic adventure novel. In this version, he is depicted as an energetic and good-hearted boy of thirteen who helps his mother, Karen, run the Admiral Benbow Inn on the coast of England. His father, a sailor, has passed away from an illness while at sea, leaving Jim with a desire to follow in his footsteps and a need to support his mother. A notable addition to this adaptation is his constant companion, a pet leopard or cheetah cub named Benbow, who accompanies him throughout his journey.

Jim is characterized by his strong sense of duty, kindness, and empathy. He is a hardworking child dedicated to his family's inn, but he is also curious and eager for adventure. His initial naivety and willingness to trust others, particularly the charismatic ship's cook Long John Silver, are central to his personality. He greatly admires Silver at the start of the voyage, viewing him as a friend and father figure. When Silver reveals his true nature as a ruthless pirate and the ringleader of a mutiny, Jim feels deeply betrayed. This betrayal forces him to navigate a sea of complex emotions; he often tries to mask his confusion with anger, yet he cannot truly bring himself to hate the man who still considers Jim a friend. Jim is fundamentally a Nice Guy who prioritizes the lives and well-being of his crewmates over the pursuit of fortune, often tending to the injured rather than focusing on the treasure.

His primary motivation for joining the voyage to Treasure Island is not greed, but a chance to make something of himself and secure rewards for his family, driven by the memory of his father. This dream is set in motion when a paranoid pirate named Billy Bones, a guest at the inn, dies and leaves Jim a map to the legendary treasure of Captain Flint. As the plot progresses, Jim proves to be clever and resourceful, but his role evolves from an innocent bystander to an active and courageous young adventurer who takes decisive action, such as secretly retaking the ship, the Hispaniola, from the mutineers.

Key relationships define his journey. His bond with Long John Silver is the most significant and complex, as it is a mix of paternal affection, admiration, and bitter betrayal. He also forms crucial alliances with the ship's owner, Squire Trelawney, the wise Dr. Livesey, and the seasoned Captain Smollett, who become his protectors and mentors. The death of Redruth, the squire's gamekeeper, is a pivotal and traumatic event that forcefully strips away Jim's remaining childhood illusions and forces him to confront the true, violent reality of his adventure.

Throughout the series, Jim undergoes significant character development, evolving from a naive boy into a more hardened and experienced individual. The constant moral confusion caused by Silver, who is both a villain and a genuine friend, forces Jim to mature quickly. He endures the horrors of a mutiny, violent combat, and the loss of lives, including a moment where he is forced to kill a pirate, Israel Hands, in self-defense. This traumatic experience is a cornerstone of his development, scarring him but also forging his resolve. He remains courageous and cunning, often using his wits to stay one step ahead of the pirates, though his plans can sometimes get him into trouble. While he shows no extraordinary abilities beyond his intelligence and bravery, by the end of the quest, he has earned the respect of his allies and rivals alike, having successfully navigated the perilous journey and secured the treasure.