Jabu is the Bronze Saint of the Unicorn constellation, a character who serves as a loyal guardian to Athena and a supporting figure within the larger group of Bronze Saints. His training grounds were in Oran, Algeria, from which he returned to Japan to participate in the Galactic Tournament hosted by the Kido family. As a child, Jabu lived in an orphanage under the care of the Graude Foundation. He displayed an almost excessive gratitude towards the Kido family for taking him in, which made him exceptionally obedient to Saori Kido. He would endure her whims without complaint, an act that led other orphans like Seiya to mock him as a lapdog. This childhood servitude, however, was rooted in genuine loyalty and devotion rather than a naturally submissive personality, as he often proved to be confrontational and arrogant with his peers.

Jabu’s personality is marked by a distinct duality. On the surface, he is proud, boastful, and confident in his abilities as a Saint. He initially acts as a rival to Seiya, looking down on the Pegasus Saint and carrying himself with a sense of superiority. He is fiercely protective of Saori, viewing himself almost as her personal bodyguard. However, his defeat at the hands of Andromeda Shun during the Galaxian Wars, followed by a swift and humbling loss to Phoenix Ikki, serves as a pivotal moment for his character. This failure forces him to retreat to his training grounds in Algeria to reflect and grow. Upon his return, Jabu is noticeably more mature and centered. He abandons his petty rivalry with Seiya and the other main protagonists, fully accepting his role in the larger cause of protecting Athena. He becomes less impulsive, recognizing when he is outmatched, yet he remains courageous, willing to stand against far stronger enemies if it means following his duty or protecting others.

His primary motivation evolves from a personal desire to gain approval and status to a pure, unwavering devotion to Athena. While his initial loyalty was to Saori as a girl, this eventually transforms into a sacred duty towards the goddess she represents. In spin-off material such as Saint Seiya Omega, his motivations expand to include protecting humanity and guiding the next generation of Saints, demonstrating a selfless resolve that sees him traveling the world to eliminate enemies while his comrades fight on the front lines.

Within the story, Jabu occupies a supporting role. While he is one of the ten Bronze Saints who return from training, he is not part of the core group of protagonists (Seiya, Shiryu, Hyoga, Shun, and Ikki). Instead, he acts as a secondary defender. During the Battle of the Twelve Temples, he stays behind to protect the wounded Saori Kido from Sanctuary soldiers, acknowledging that his power is insufficient to storm the temples like the main heroes. In later arcs, such as the Asgard and Hades sagas, he takes on the role of a guardian of Sanctuary, fighting off lesser enemies and specters. In the film Tenkai-hen, his loyalty is shown to be complex, as he and other Saints serve Artemis, though this is considered a controversial departure from his usual character. In Saint Seiya Omega, set decades later, he has retired to a quiet life as a farmer but returns to battle as a Steel Saint, a testament to his enduring sense of duty.

Key relationships define much of Jabu's actions. His most significant bond is with Saori Kido, for whom he feels both intense loyalty and a hidden romantic affection, a motif that echoes the mythological unicorn which is said to be tamed only by a pure maiden. He shares a relationship of mutual respect with Tatsumi, the Kido family butler. His dynamic with Seiya shifts from intense rivalry as children to a solid, if understated, camaraderie in adulthood. He also briefly acts as a mentor to Sōma, the Lionet Saint, in Omega, passing on his fighting philosophy and techniques.

In terms of abilities, Jabu possesses full control over the energy known as Cosmos, a requirement for all Saints. His signature technique is the Unicorn Gallop, a powerful attack that involves delivering a flurry of kicks at the speed of sound. In the anime adaptation, he is also depicted with telekinetic abilities that allow him to move and cut objects with his mind, a power not present in the original manga. While he generally operates at a Bronze Saint level, he demonstrates considerable physical resilience, such as surviving attacks from the god Thanatos, and in later appearances like Omega, he proves capable of defeating powerful Pallasite soldiers. His endurance and growth allow him to survive battles that claim many others, solidifying his reputation as a reliable, if not always central, warrior for Athena.