J-3DI, also known as Jay-Threedeeaye or, more simply, Jay-Three, stood out as a rather peculiar droid. His programming led him to genuinely believe he was both a Jedi Knight and a wielder of the Force. His exterior featured plating designed to resemble Jedi robes, and he brandished a blue colored lightsaber. He was the brainchild of Sprocket, another competitor, specifically crafted to mirror Rieve, a Force-sensitive contestant. He was loaded with a comprehensive Jedi wisdom database; though unable to actually use the Force, he could replicate its effects using technology. Due to limited information available about the Jedi by 9 ABY, his programming frequently contained errors in Jedi history, resulting in misquoted Jedi sayings. J-3DI participated in the Hunters of the Outer Rim competition, which took place on the planet Vespaara.
During the initial period of J-3DI and Rieve's time as Hunters, Rieve often grew irritated by J-3DI's personality and his vast databank of information. Her initial disdain for J-3DI, exaggerated for the audience, and his role as her opposite, caused Rieve to obsessively target the droid during their early matches. This focus led to her team's defeat. J-3DI quickly identified this strategy and intentionally provoked her into pursuing him, giving his team an advantage. In response to her lack of teamwork, Daq Dragus, co-owner of the competition, personally assisted in Rieve's training, with J-3DI's help. Dragus showed Rieve that surprise attacks were J-3DI's biggest weakness. Using his flawed Jedi knowledge database, J-3DI began calling Rieve his apprentice and Padawan, given their training sessions. This further aggravated Rieve's annoyance with the droid.
When a mysterious figure started appearing to Rieve, following incidents of sabotage to her gear, J-3DI was quick to offer his assistance. He suggested scanning the crowds for individuals matching the figure's description and helped search the Grand Arena when the mysterious figure was spotted in restricted areas. When the man's henchmen attacked the arena, seeking maximum destruction, J-3DI stood on the front lines, defending against the invaders. Alongside Balada, he helped search the arena's underbelly for the mysterious man. After Rieve deflected a class-A thermal detonator's blast using the Force, she suffered severe burns, and J-3DI was the first to rush to her side to check on her. After these events, he and Rieve became closer backstage.
In spite of this newfound closeness, the rivalry between J-3DI and Rieve was destined to reignite, and Rieve challenged the droid to a fight. Rumors circulated that this was because J-3DI had requested Rieve to become his apprentice, a rumor that Rieve did not deny.
Although Rieve ultimately won the battle, J-3DI didn't seem to mind. Rieve reluctantly helped him gather his scattered parts from the floor. When tensions between fellow Hunters Aran Tal and Imara Vex escalated, a brawl erupted in the Arena's Chow room. J-3DI attempted to stop Tal, but the Mandalorian simply pushed Grozz onto the droid. Daq Dragus was compelled to step in and halt the fight.
J-3DI was present during the initial encounter between Sentinel, an Imperial loyalist, and Pilbush, a Rebel enthusiast. Because Pilbush was an Ewok who only spoke Ewokese, J-3DI translated her remarks to Sentinel, although he deemed her comments so inappropriate that he chose not to translate them entirely. Pilbrush and Sentinel's relationship only worsened from that point. After losing a Clash against Sentinel, Pilbush continued her training with J-3DI and her other friends.
J-3DI made his debut in the canon video game Star Wars: Hunters as a playable character. The game was developed by NaturalMotion's BossAlien and published by Zynga on November 16, 2021, as a soft launch in select countries, before its global release on June 4, 2024. Ross Burt, a concept artist, designed the droid.