S.G.S Foundation (The Boukengers)
Satoru Akashi / Bouken Red | Actor: Mitsuomi Takahashi
The Fiery Adventurer, as Bouken Red he drives Go Go Dump and leads the team with a calm expression and a fire in his heart. He mostly battles against Ryuuwon of the Jaryuu Tribe. He is often called Chief
by the other Boukengers.
- Butt Monkey: Eventually developed a mild case while maintaining his cool persona. An entire episode was dedicated to taking this trope to the extreme, by way of a bad luck curse.
- Not Quite Dead: After seemingly exploding with the Precious Bank, Satoru appears safe on the Dai Voyager in time for the final battle due to Zuuban.
Masumi Inou / Bouken Black | Actor: Yasuka Saito
The Fast Adventurer, as Bouken Black he drives Go Go Formula, a racecar-like vehicle, and is only part of the Boukengers to pay his debt back to Akashi for saving his life. He has a personal vendetta against Yaiba of Darkness of Dark Shadow.
Souta Mogami / Bouken Blue | Actor: Masashi Mikami
The High-Up Adventurer, as Bouken Blue he drives Go Go Gyro, an airplane-like vehicle, and serves as the team's information specialist. Before he joined the Boukengers, he was an international spy which is why he's so effective at finding info. He often finds himself fighting (and flirting with) Shizuka of the Wind of Dark Shadow.
Natsuki Mamiya / Bouken Yellow | Actress: Chise Nakamura
The Strong Adventurer, as Bouken Yellow she drives Go Go Dozer, a giant bulldozer, and is the most childish of the group. Her main reason to adventure was to discover more about her own past. It is later revealed that she is the last survivor of the Lemurian civilization.
- Japanese Pronouns: Averted.
- Played straight in Episode 14 (uses "Atashi") and when brainwashed in the Lemurian Princess episodes (uses "Ware").
Sakura Nishihori / Bouken Pink | Actress: Haruka Suenaga
The Deep Adventurer, as Bouken Pink she drives Go Go Marine, a giant submarine, and is the most serious member of the team when it comes to work. She often appears to be cold and emotionless, but cares for her teammates. Before she joined the Boukengers she was in the special forces of the military.
- The Lancer: being Satoru's second-in-command and her strict, no-smiling personality contrasts with his outgoing, inner-Hotblooded personality.
- When She Smiles: It's adorable. Plus, as Satoru said, it's one thing only she possesses, and it becomes her greatest treasure in the end.
Eiji Takaoka / Bouken Silver | Actor: Masayuki Deai
The Dazzling Adventurer, as Bouken Silver he drives Go Go Fire and serves as the spiritually strongest of the team because his father, the Ashu Watcher Kando wed with the Ashu Kei, making Eiji half-Ashu
. He mostly battles against Gai (as either form) due to their bitter history. In Boukenger vs. Super Sentai
, he embodies Hope.
Negative Syndicate (The Villains)
High Priest Gajah of the Gaodom Civilization | Actor: Hiroo Otaka
The priest of a long-dead civilization, who the Boukengers accidentally reawaken in the first episode. Desires to revive his country by conquering the Earth
- Big Bad: Eventually, after every other villain gets taken care of.
- Laughably Evil: When one of your plans involves stealing from Santa Claus, it's hard not to fall into this.
- Mook Maker: Can spawn his Karths out of any stone.
- Orcus on His Throne: Gajah owns no specific Monster of the Week to call upon, and can't really fight on his own, so he usually stays in the background, only striking with well-thought out schemes... Until some of the final arcs
- Took a Level in Badass: Early episodes, he gets beat up easily each appearance he makes, Ryuuwon just walking into his lair threatening information of out of him. By the finale, he adds three Godom engines to himself and beats the tar out of Ryuuwon and the Boukengers, and that's before his One-Winged Angel where he gets the Heart of Godom
Creator King Ryuuwon of the Jaryuu Tribe | Actor: Junpei Morita
An ancient once-human adventurer who transfigured himself into a dragon after being betrayed by his comrades. He despises humanity, and wishes to create a world where only the truly worthy may survive. Often fights against Akashi, due to their similarities.
- The Dragon: Literally. In respect to the trope, though, he's not a straight example (seeing as he works independently), but he's one of the stronger villains in combat, often takes to the battlefield himself and is the next to last villain to bite it.
- Homage: His design is based on Daizyujin from Kyoryu Sentai Zyuranger.
- Mook Maker: Is able to create his Jaryuu soldiers from samples of his own body.
- Shadow Archetype: Ryuuon represents a darker side of Akashi, an adventurer that was ridiculed and ended up seeking more power for the revenge of his ridicules in the past.
- Social Darwinist: Watch how he creates his Jakuryuu, by making his mooks kill each other and then transforming the winner.
A group of Japanese-based thieves who are out to make big bucks by stealing Preciouses. Consist of Maboroshi no Gekkou (owl), Kaze no Shizuka and Yami no Yaiba.
- Anti-Villain: They're called Dark Shadow, they're antagonists, but they're the least evil amongst the Negative Syndicate since Gekkou and Shizuka are not interested in causing harm to humanity unlike Gaja, Ryuuon or the Questers, they just want to make a lot of money and can be shown to be friendly to the Boukengers. Yaiba, on the other hand...
- Knight of Cerebus: Yaiba, the first completely serious villain we get in the series.
- Make My Monster Grow: Gekkou is the most reliable source of this trope with his 'Oogami Henge no Jutsu.
- Ninja: Yaiba and Shizuka.
- Token Evil Teammate: Gekkou and Shizuka can be sympathetic and look like 'just doing their job'. Yaiba is the only straight up villain as he is a darkness-worshipping guy who ends up betraying the whole team for the power of darkness.
A group of Ashu demons out to make humans suffer and take over the human world. It has a whole army, but only two are in the world: Rei and Gai. They were quickly defeated but came back more powerful and mechanized when Gaja gave them the Godom Engine. They quickly broke out of Gaja's services and worked on their own. They're Eiji's Arch-Enemy
- Evil Counterpart: They were made into Questers by Gajah using research on the Boukenger's Parallel Engines. Their Quester forms and Swiss-Army Weapon also look vaguely Rangerlike. And to top it off, they also use Humongous Mecha during each of their appearance, instead of going for human sized monsters that grow bigger upon defeat.
- Evil Is Not a Toy: Gaja revives them with the Godom Engines, but didn't actually come up with a plan to control them.
- Homage: To nearly all the mecha of Gosei Sentai Dairanger. Gai is Ryuuseioh, Rei is Won Tiger, Quester Gai is Dairenoh, Quester Rei is Kiba Daioh, and Hyoga is Daimugen.
- Humongous Mecha: The Quester Robos, most of which were designed specifically to use a particular Precious.
- Knight of Cerebus: Are treated as the biggest threat in the show and tend to be the toughest to fight ironically are the first to die.
- Not Quite Dead: Their apparent status between being killed as Ashu and revived as Questers.
- Sealed Evil in a Can: Rei was trapped in a mirror, along with the rest of the Eastern Ashu, until Gai and Hyouga found a way to bring Rei back.