- Adaptational Expansion: He is given much greater character exploration than he is in the games, largely owing to being able to speak, rather than communicating with ellipses.
- Badass Adorable: Like with his game counterpart, he takes down an entire criminal organization during the course of the series. He did so at the tender age of 11.
- Beware the Nice Ones: Giovanni learned that the hard way when Red took him down in the Viridian City gym.
- Brains and Brawn: Brains to Blue's Brawn. He's more focused on filling the Pokedex whereas Blue just wants to battle his way to the top.
- Curtains Match the Window: His hair and eyes are the same shade of brown.
- Berserk Button: He does not take the abuse of Pokémon very well. It goes so far that he refuses to take the final badge from Giovanni at first due to his involvement in Team Rocket.
- Ditzy Genius: He's a very smart kid who is more into researching and collecting Pokémon. However, he seems to keep forgetting type match ups, even into the champion battle.
- Disappeared Dad: We get a slight hint about his dad. Red openly talks about him, but not in a nostalgic way implying Red's Dad is around, just not home a lot.
- The Fettered: It's to the point where he initially refuses the Earth Badge because the guy giving it is a crimelord.
- Hot-Blooded: Played with. He is Hot-Blooded, but he's also a Blue Oni.
- Keet: He can be quite excitable sometimes.
- The Klutz: Professor Oak actually says this is a Disability Superpower because it's required Red to take it slow and learn to analyze how to do things and thus be more adaptive to his environment.
- Meaningful Name: It's revealed his dad named him Red because red is the color of love and warmth.
- Mythology Gag: Among other things, his team when going up against the Elite Four (Charizard, Persian, Dodrio, Scyther, Lapras and Jolteon) was the same as that of series creator Satoshi Tajiri when he cleared the game for the first time.
- Nice Guy: A kind-hearted and friendly guy at heart. He is willing to help others in need, even for his rival, Blue.
- Nice Hat: His trademark red cap.
- Perpetual Frowner: His battle face is one of these. Outside of battle he's very happy and smiley.
- Red Oni, Blue Oni: Ironically, he's a Blue Oni to Blue's Red.
- Took a Level in Badass: He begins as a noob in the first episode who makes common mistakes like throwing a Poké Ball at another trainer's Pokémon and finds himself on the receiving end of a Curbstomp Battle. He gradually learns over the course of the series, training with his Pokémon and learning new tactics that eventually help conquer the Pokémon League and his rival. Once his bond with Charizard got strong enough in a battle against Mewtwo, he managed to unleash Mega Charizard X, a Pokémon capable of whooping Mewtwo's ass.
- Weapon of Choice: Charizard, and to a lesser extent, Jolteon.
Blue Oak (Green Ookido)
- Adaptational Jerkass: Blue's characterization is extra dickish compared to his in-game portrayal. Most of his dialogue is him insulting Red, Red's Pokémon, Team Rocket and so on, while being a Dirty Coward.
- Brains and Brawn: The Brawn to Red's Brains—he's less interested in filling the Pokedex and more interested in battling his way to the top.
- Break the Haughty: His losses against Red and Mewtwo humble him, immensely.
- Crouching Moron, Hidden Badass: He can be surprisingly cowardly at times but his battling skill is quite remarkable. Let's not forget that he became the Champion first.
- Curtains Match the Window: His hair is a lighter tone of brown than his eyes though.
- Deadpan Snarker: Blue mocks Red's choices and actions through the series, calling him predictable or childish. The most notable example is when he choose his starter. When Professor Oak asks him if he would choose a Starter based on his name, Blue simply scoffs it as being a silly reason and simply chose his starter, Squirtle, because a Water-type has the advantage over the Fire-type Charmander Explanation
- Disc-One Final Boss: Although the series built Blue up as the final opponent for Red, he is defeated halfway through 4th episode and the remainder deals with the True Final Boss, Mewtwo.
- Jerk with a Heart of Gold: He's an arrogant, condescending asshole, sure — but it's clear that he does view Red as a good friend on some level.
- Red Oni, Blue Oni: Weirdly enough, he's the Red Oni.
- The Rival: To Red.
- Tsundere: He clearly respects Red by the end of the series... although he'd never admit it out-loud.
- Weapon of Choice: Blastoise.
Professor Oak (Dr. Ookido)
- Berserk Button: Do not treat your Pokémon with contempt or call them morons in front of him.
- Gotta Catch Them All: His long life dream is to see his Pokédex being complete, and he entrusts Red and Blue to finish it.
- Vocal Dissonance: He sounds much younger than he looks, which can be a bit jarring for viewers familiar with the anime version.
- Big Brother Mentor: Brock acts as one for Red. After witnessing Red lost his first Pokémon Battle to Blue, Brock came to Red and encourages him to go the Pewter Gym to improve himself there. During their Gym Battle, Brock lectures Red the importance of skill, strategy, and bond of the trainer and his Pokémon.
- Dishing Out Dirt: His Gym specializes Rock-Type Pokémon.
- Eyes Always Shut: It's not Brock without them.
- Weapon of Choice: Onix.
Voiced by: Minoru Inaba (JP), Kirk Thornton (EN)
- The Atoner: Implied by one of his gifts to Red, a Mega Stone which proves to be vital against Mewtwo, a Pokémon that he was involved in creating.
- Dark and Troubled Past: He was once known as Dr. Fuji, a famous scientist who was involved in the creation of Mewtwo.
- Distressed Dude: Like in the games, he gets captured by Team Rocket in the Pokémon tower.
- Friend to All Living Things: He takes care of abandoned and orphaned Pokémon, such as Cubone.
- Adaptational Heroism: Giovanni is portrayed more sympathetically compare to various other adaptations, including the games. While a villain nonetheless, here he is mostly motivated by business and greed rather than personal power and world domination. This is best demonstrated in his reaction after losing to Red. In the games, Giovanni disbands Team Rocket because he feels unworthy to be its leader after losing to a young kid three times and swears to become a better trainer. It was later revealed in HeartGold and SoulSilver that he had never truly abandoned his old ambitions and sought to revive Team Rocket after his training. In Origins, Giovanni remembers the fun of Pokémon battles from his childhood, and realizes that treating Pokémon as tools for business was wrong all along. He then disbanded Team Rocket to atone for his mistakes, and to create a new path for himself and his Pokémon.
- Audience Surrogate: He represents the OVA's target audience, older fans that grew up with Pokemon.
- Authority Equals Asskicking: He isn't the Rocket Boss and the Viridian Gym Leader for nothing.
- Badass Baritone: His voice has calm yet deep demeanor, rarely ever raising to a higher tone.
- Badass in a Nice Suit: Giovanni wears the classical black business attire with an R insignia on his left side. As Red finds out, Giovanni is an exceptionally tough and merciless trainer, able to Curb Stomp nearly all of Red's entire team with just one Pokémon.
- Big Bad: He's the overarching Big Bad of the series, while Mewtwo was more of a Diabolus ex Nihilo.
- Corrupt Corporate Executive: Naturally to be expected from the boss of a criminal organization. Much of Giovanni's plans involve poaching Pokémon, using Pokémon for experiments, and taking another company hostage just to obtain new technology to catch more Pokémon all in the name of making profits for his business. He even refers Pokémon as just "business" and doesn't understand why Red would see them as something more until he rediscovers his old passion during the final Gym Battle.
- Hidden Depths: His gym battle with Red slowly, but surely, brings out his dormant Hot-Blooded nature and passion for Pokemon training that he had forgotten for years.
- Heel–Face Turn: Performs one after his battle with Red, realizing Red's view of Pokémon as more than tools to commit crimes is right.
- Lack of Empathy: Giovanni shows no emotions when Red asks why would he harm Pokémon, simply saying that Pokémon means business and that it requires a little sacrifice to maintain that business. Subverted in his Gym Battle when Giovanni realizes he's empathizing with Red's determination and passion.
- Weapon of Choice: The Rhyhorn line: both Rhyhorn and Rhydon.
- Ambiguous Gender: Though if it's anything like it's game counterpart, it most likely doesn't have one to begin with.
- Animalistic Abomination: Acts more like an uncontrollable monster than the sophisticated and misunderstood creature it is in the main series, and is already a manmade unnatural creature that went horribly awry.
- Ax-Crazy: It attacks Red and Charizard pretty much the moment they show up to challenge it.
- Berserk Button: It wasn't friendly to begin with, but the first time Red throws an Ultra Ball at it? It's enraged.
- Diabolus ex Nihilo: Its purpose is largely just to show how good a trainer Red is.
- Perpetual Frowner: It's always angry.
- The Worf Effect: It took down Articuno!