Borsalino, widely known by his alias Kizaru, is a character who appears as a formidable presence in One Piece Film Z. He holds the rank of admiral in the Marines, a position that places him among the organization's most powerful officers. His real name is Borsalino, and his alias Kizaru translates to Yellow Monkey, a reference to his yellow-themed attire and the power of his Devil Fruit. Born on November 23rd, he is a native of the North Blue and is notably the oldest of the original three admirals, a fact subtly reflected in the deeper wrinkles on his face.

In terms of appearance, Borsalino is a tall and slender man with curly black hair, a light beard, and thick lips. He is rarely seen without his signature round amber-lensed sunglasses with a yellow frame. His typical outfit consists of a yellow vertically striped suit, worn under a standard Marine coat draped over his shoulders. A dark-colored shirt and a mauve tie complete his usual ensemble. However, in One Piece Film Z, his costume is altered slightly for a more casual look; he replaces the shirt and tie with a dark green turtleneck sweater, though he retains his distinctive yellow suit and coat.

The personality of Borsalino is one of his most defining characteristics, marked by a stark contrast between his demeanor and his abilities. He possesses an extremely relaxed, aloof, and absent-minded temperament. He speaks in a very slow, drawn-out manner, often trailing off at the end of his sentences and using phrases like ooh and nee. This lackadaisical attitude makes him appear perpetually unconcerned, even in the most dangerous situations. Despite this lazy facade, he is utterly ruthless when it comes to fulfilling his duty. He shows no mercy to criminals, believing that the crimes of pirates do not fade or disappear with time. His particular brand of justice is described as uncertain justice, a philosophy not bound by rigid principles but rather determined by personal, unpredictable choice. A common verbal tic is his sarcastic habit of calling his opponents' abilities or resolve scary or monstrous, all while maintaining an expressionless face and a calm tone, which suggests he is either mocking them or giving a backhanded compliment.

Within the Marine hierarchy, Borsalino maintains a casual yet professional relationship with his fellow admirals, often acting as a mediator between the more hot-headed Sakazuki and the more passive Kuzan. He has a notably close relationship with Sentomaru, the commander of the Marine's science unit, who respectfully refers to him as uncle, a term echoing the relationship between a yakuza boss and his subordinate. Despite this respect, Sentomaru has no issue openly scolding the admiral for his carelessness, such as when Borsalino attempts to use a den den mushi designed for eavesdropping to make a regular call. The most pivotal relationship explored in Film Z is with Zephyr. In his youth, Borsalino was a student of the legendary Marine instructor known as Zephyr. Their compatibility was described as the worst, and it is implied their relationship was never good, making their eventual confrontation as enemies deeply personal.

The role of Borsalino in One Piece Film Z is that of a central secondary antagonist and the primary opposition to the film's main villain, Zephyr. He is sent by the Marine headquarters to stop his former instructor and the Neo Marines. His motivations in the film are straightforward and professional: to uphold Marine justice and eliminate a threat to the world's stability, even if that threat comes from a man who was once his teacher. He shows no hesitation in his mission, acting as the unwavering arm of the World Government.

Throughout the film, Borsalino's character is developed primarily through his actions in combat against Zephyr. Unlike his usual habit of toying with weaker opponents, this battle forces him to fight seriously. The confrontation with his former mentor is the key to his development in the story, as it strips away his usual sarcastic and aloof demeanor, revealing a focused and deadly combatant. The film highlights that Zephyr is one of the few people who can push Kizaru to such an extent. In the film's climax, after the Straw Hat Pirates have defeated Zephyr's subordinates and Luffy has broken Zephyr's resolve, Kizaru arrives with a massive fleet of Vice Admirals and Marines. He directly engages the exhausted Zephyr, delivering a powerful Yasakani no Magatama attack and ultimately being the one to corner his former teacher in his final battle.

In terms of notable abilities, Borsalino is a user of the Pika Pika no Mi, a Logia-type Devil Fruit that allows him to transform his body into light. This grants him the power to move, fly, and attack at the speed of light, making him one of the fastest characters in the series. He can fire concentrated beams of light from his hands and feet that cause massive explosions, and he can create a sword of pure light, called Ama no Murakumo, for close-quarters combat. He also utilizes techniques like Yata no Kagami, where he reflects his light form between surfaces to achieve high-speed travel, and Yasakani no Magatama, his signature attack where he unleashes a devastating shower of light particles. In One Piece Film Z, he employs his full arsenal of these light-based techniques in his climactic fight against Zephyr, demonstrating his immense destructive power. Even the use of a Dyna Stone, a weapon of mass destruction, does not harm him, showcasing his invincibility to conventional weaponry.