Jason, known in the original Japanese version as Joe Asakura or Condor Joe, serves as the second-in-command of the Science Ninja Team Gatchaman, designated as G-2, with the condor as his symbolic bird motif. He is an eighteen-year-old orphan, a background that has significantly shaped his fierce independence and drive. Outside of his duties, he lives a civilian life as a professional race car driver, towing a small trailer from competition to competition, and he maintains a high-performance stock car that doubles as his personal vehicle, the G-2.

In terms of personality, Jason is often perceived as the antithesis of the team's leader, Mark. He is frequently described as impulsive, hot-headed, and a classic "bad boy" who prefers to shoot first and ask questions later. This perception, however, belies a more complex individual. His defining trait is a profound sense of independence; he insists on thinking for himself and questions authority when orders seem illogical or morally questionable. Rather than simple insubordination, this reflects his demand for legitimate and accountable leadership. He possesses a serious work ethic, driven by a hard-eyed idealism that finds the Spectran attacks fundamentally obscene. He is the team member most likely to advocate for saving ordinary civilians, not out of a sense of abstract heroism, but from a deep-seated conviction that their lives are what the team is fighting to protect.

Jason's core motivation stems from a deep-seated hatred for the enemy, Galactor (or Spectra), a feeling exacerbated by the loss of his parents to one of the organization's spies. He is a natural fighter who believes that a fast, decisive strike is usually the best strategy, and he thinks exceptionally well on his feet in the heat of battle. While he respects legitimate authority, he has no patience for incompetence, regardless of rank, and is willing to take charge if a situation demands it. This has led to a dynamic relationship with the official leader, Mark, often involving friction and frequent reminders of their respective positions. However, this tension coexists with deep loyalty, and Jason shows considerable heart and compassion for his teammates beneath his tough exterior. In his personal life, he tends to fall for the wrong women, most of whom are often undercover enemy agents, leading to a series of doomed romantic encounters.

Jason undergoes significant development throughout the series. A notable turning point occurs when he is severely wounded by shrapnel, which affects his brain. His hatred for Galactor drives him to try to destroy the organization before his own life expires. After his apparent death, he is found and resurrected as a cyborg by Doctor Raphael, which grants him a form of immortality and removes his fear of death, allowing him to fight even more recklessly. He also demonstrates a capacity for growth in his skills, gradually becoming a highly competent pilot of the team's mecha, the Phoenix, despite initial difficulties.

As a combatant, Jason is the team's designated weapons expert and sharpshooter, possessing hawk-like accuracy. He is never without his primary tool, the Multi-Purpose Gun, which can function as a cutting torch, a drill, and can fire a grappling cable mechanism. His signature projectile weapons are the Feather Shuriken, which he can deploy as throwing daggers, darts, or even explosives. When transformed into his birdstyle combat suit, his abilities are greatly enhanced. He gains the power of flight or gliding, and his most notable technique is the Tornado Fighter, where he spins at high velocity to create a destructive cyclone powerful enough to combine with his teammates' attacks for a greater effect. His agility, endurance, and senses are also heightened to superhuman levels in this form.