Franklin Harlock Jr., often referred to simply as Harlock, is a central figure in the anime Gun Frontier, presented as a gunslinger and a former sea captain. His background reveals that he once operated as a pirate on the high seas before arriving on the shores of the American Old West. A defining moment in his past is a duel with the samurai Tochiro Oyama, during which Tochiro inflicted the distinctive X-shaped scar on Harlock’s cheek. Despite being enemies at the time, Tochiro ultimately saved Harlock’s life, an act that forged a deep and unbreakable bond of loyalty between the two men. As a result, Harlock, who owes his life to Tochiro, accompanies him on his journey across the lawless frontier known as the Gun Frontier.

In terms of personality, Harlock is predominantly quiet, enigmatic, and taciturn. He is a man of few words, often dismissing inquiries about his past with a grumble or remaining silent. This stoic demeanor makes him appear rough and somewhat careless, yet it masks a sharp and perceptive mind. He is notably more talkative and less dark than his space-faring counterpart in other stories, fitting the more adventurous tone of Gun Frontier. As a master gunman and a quick draw unlike any other, he is supremely confident in his abilities, rarely missing a target, which allows him to navigate the violent and hostile environment with a sense of calm invincibility.

Harlock’s primary motivation is intrinsically linked to his relationship with Tochiro. While the overarching quest is to find the scattered survivors of the Samurai Creek, a Japanese immigrant town that was massacred, Harlock’s role is that of a loyal protector and partner. He does not seek the lost clan for his own reasons but supports his friend’s mission without hesitation. He accompanies Tochiro as they travel from town to town, taking on odd jobs such as bounty hunting to survive in the brutal landscape. In a significant departure from many other works by Leiji Matsumoto, Harlock serves as the sidekick in this story, with the narrative focusing more on Tochiro as the protagonist.

The cornerstone of the story is Harlock’s key relationship with Tochiro Oyama. The two are a mismatched pair who play off each other perfectly; where Tochiro is respectful and wears his heart on his sleeve, Harlock is quiet and reserved. Yet, their loyalty is absolute, with Harlock invariably using his gun skills to save Tochiro whenever a sword cannot solve the problem. This bond is tested by the arrival of a mysterious woman, Sinunora, who joins them on their journey. Harlock is immediately suspicious, keenly detecting that she has her own unclear reasons for attaching herself to them and may be trying to drive a wedge between the two friends. This perceptiveness highlights his role as the more guarded and pragmatic member of the trio.

Throughout the series, Harlock himself undergoes minimal overt development, remaining an enigmatic figure. His past is revealed in fragments, most notably the origin of his scar and his debt to Tochiro, but he otherwise maintains his stoic and capable persona. His notable abilities are almost exclusively tied to his expert gunfighting skills. As a former sea pirate, he is also likely resourceful and adaptable, but his primary contribution to the group is his peerless marksmanship and ability to remain calm and analytical in the face of danger, always ensuring he and his companions survive the treacherous Gun Frontier.