Cool Plane: A Cessna plane that transforms into a supersonic jet. Supposedly operational underwater like the God Phoenix.
Disappeared Dad: His father, Kentarou, abandoned him when he was young. It turns out he was going undercover as Red Impulse, and wanted to keep his son and only relative safe. And later he does die for real, just as Ken had found out who he was *and* they were starting to rekindle their relationship. This death was smoothly erased in Battle of the Planets. His father is described as having ejected at the last minute, though of course their reunion is off-screen. The whole thing is a variation on Luke, I Am Your Father, since the reveal is done by the son's comrades and its effect is positive.
Mr. Fanservice: To a lesser extent than Joe, but his big blue eyes and boyish good looks score him points.
Hilariously Abusive Childhood: Ken has a flashback about his younger days with his father which shows once scene of his dad attempting to drown him for fun.
Anti-Hero: Mainly a Type III with some slant towards Type IV, since he has no qualms with killing Galactors in cold blood for the cause. (The others will kill too, but more out of necessity rather than satisfaction.)
But Not Too Foreign: Averted. Despite his Japanese surname, Joe is Italian (Sicilian, to be specific). That's because "Joe Asakura" is a false name to protect him from Galactor, his real name is George.
Knife Nut: The ninja equlivent of this. While the entire team carry pointy tipped feather shuriken, Joe uses them so much more often than the rest that they become his trademark weapon. He's fond of letting them hang out of his mouth like toothpicks and attacking with Twang Hello or Knife Outline
Shipper on Deck: During the finale, before his imminent death while giving his final speech to the team, he professes that Jun should settle down with Ken.
Trigger Happy - Joe is almost unhealthily eager to fire the God Phoenix's Bird Missiles, which Ken has to constantly restrain him from doing when they don't have authorization. In one episode, he keeps hammering the fire button well after the ship exhausted its supply until the realization that yes, we are OUT of Bird Missiles finally sinks in.
Weapon of Choice: He uses a Grappling-Hook Pistol, which has a grapple from the front and and weighted one from the back. One mook found out the hard way when he pointed the barrel end of it at Joe after snatching it from him, not realizing that the triggers were switched. He got thrown across the room by it after pulling the trigger, knocking him out.
On top of that, the front can be interchanged to fire conventional bullets or power a portable drill for cutting things.
Also the primary user of the ninja team issued feather shuriken.
Jun a.k.a. G-3, Jun the Swan
Sole female member of the Science Ninja Team. Demolitions expert. The Chick (usually).
Action Girl or Faux Action Girl: Depending on the script. Still, she can kick as much Galactor ass as her male teammates. And let's not forget she was quite the revolutionary figure in anime gender roles, as one of the first girls who fought alongside the boys.
BadassBiker Babe: She can pull off some rather impressive stunts on a bike.
Intensified in the OVA remake where her chest is dramatically enlarged and her outfits are much more revealing compared to the original. (And a naked Transformation Sequence, natch.)
Panty Shot: Constantly, thanks to her very short skirt.
She-Fu: Justified as it goes along with the team's fighting style. The male characters will also use flips and cartwheels to dodge/maneuver around (even Ryu can come off as being agile).
She's Got Legs: As shown off by the lower half of her birdstyle.
Wise Beyond Their Years: Somewhat. Not so much in maturity level, but the fact that he can handle various adult tasks like cooking and driving cars at age 9.
You Gotta Have Blue Hair - He has plain brown hair in the original series and sequels, but the OVA gives him wild, two-toned hair: blond on the bottom, PINK on top.
Dr. Kozaburo Nambu
Head Scientist for the International Science Organization (ISO). The Mentor.
Mauve Shirt - Red Impulse's two subordinates, Onishi and Masaki. Both manage to outlive their commander and resurface at the tail end of the series to help out the Science Ninja Team (Joe in particular). Unfortunately they are also brought back to be brutally killed.
The masked head of the criminal organization Galactor.Later revealed to be a fusion of male and female twins resulting in a mutant that can change gender at will. The Dragon.
The Reveal: Near the end of the first season finale we found his true identity as an alien who can shapeshift genders at will. Nambu finds s/he has an IQ of 280, not because of being that smart, but because s/he has two I Qs at the same time.