''Juukou B-Fighter'' is Toei's 14th entry in its ''Franchise/MetalHeroes'' series, and the first of its ''B-Fighter'' series. Its footage was used to create ''[[Series/{{Beetleborgs}} Big Bad Beetleborgs]]''.

Whilst investigating a sudden mass swarming of insects, researcher Takuya Kai of the Earth Academia meets the mystical Insect Elder Guru. He tells him that the insects sense the invasion of the extra-dimensional Jamahl Empire, and are preparing to fight them. With Guru's help, Takuya and his mentor Professor Mukai develop three PowerArmor suits infused with the power of beetles. One suit is entrusted to Takuya, the other two to Daisaku Katagiri and Rei Hayama. They become the B-Fighters, who regularly oppose the schemes of Jamahl and its three generals.

!!The B-Fighters:
* Takuya Kai/'''Blue Beet''': TheLeader; an insect researcher from Earth Academia who is the first to learn of Jamahl's evil schemes.
* Daisaku Katagiri/'''G-Stag''': [[TheBigGuy Big]] [[TheLancer Lancer]]; a tree doctor who claims to hear the voices of trees.
* Rei Hayama/'''Reddle''': [[FragileSpeedster Fragilistic]] [[TheChick Chick]]; an animal instructor. [[PutOnABus She left to do animal research in South America]] and was replaced by [[TheHeart Mai]] [[FriendToAllLivingThings Takatori]].

* Insect Elder Guru: TheMentor.
* '''Kabuto''': [[TheSixthRanger Essentially, the fourth B-Fighter]]; Guru's Beetle-armored son who left him to pursue a career as a weapons supplier.

!!Jamahl Empire:
* Emperor Gaohm: The BigBad
* Jera: The DarkChick
* Schwartz: The robotic EvilGenius
* General Gigaro: TheBrute
* Sorceress Jagul: Another EvilGenius; the SixthRanger responsible for Shadow's creation. [[spoiler:Actually killed off shortly after, but comes back once every other villain is dead.]]
* Shadow/'''Black Beet''': Takuya's [[EvilTwin Evil]] [[CloningBlues Twin]].

!!''Juukou B-Fighter'' provides examples of the following tropes:

* AllYourPowersCombined: Jagul [[spoiler:absorbs the powers of various monsters to assume her OneWingedAngel form.]]
* BackFromTheDead: [[spoiler:Jagul revives [[Series/TokusouRoboJanperson Bill Goldy]] and [[Series/BlueSWAT Queen]] as pawns near the finale, then absorbs them into her OneWingedAngel form.]]
* BadBoss: [[spoiler:Gaohm's methods for completing the Jamahl Hole end up costing Gigaro and Schwartz their lives. He also kills Jera for seeing his true form.]]
* BerserkButton: Do NOT attempt to cut down a tree when Daisaku is nearby.
* ByThePowerOfGrayskull:
** "''Juukou!''" ("Heavy Shell!")
** "''Jakou!''" ("Evil Shell!") for Black Beet.
* CallingYourAttacks
* {{Crossover}}: The final episodes featured Series/BlueSWAT and [[Series/TokusouRoboJanperson Janperson]] aiding our heroes.
* DraggedOffToHell: [[spoiler:Jagul gets this from Bill Goldy in the finale.]]
* DragonTheirFeet: [[spoiler:Jagul comes back in the finale to serve as the FinalBoss.]]
* DropTheHammer: The motif of episode three's monster.
* EverythingsBetterWithSpinning: The B-Fighters' weapons all spin when activated.
* GrandFinale: With shades of FullyAbsorbedFinale, as Janperson and Gun Gibson, plus the Blue SWAT team, all assist the B-Fighters in the final battle.
* GreenAesop: Although it decreases over time, the show often focused on damage being done to the environment, with most of the B-Fighter's weapons and equipment being infused with insect powers.
* HumongousMecha: The Beet Machines, a trio of beetle-themed vehicles, and Mega Heracles, a gigantic mechanical Hercules beetle.
* JapaneseBeetleBrothers: Blue Beet and G-Stag are a Type A.
* TheManBehindTheCurtain: [[spoiler:The Gaohm we see for most of the series is actually a dummy, with the true Gaohm being an entity contained in a tank full of liquid.]]
* MidSeasonUpgrade: Blue Beet's Beet Ingram gun, which allows him to transform into Super Blue Beet.
* MindScrew: The Gaohm Zone. The fight scenes which take place in it range from slightly weird to flat-out insane. Some parts (such as one instance where G-Stag ends up getting randomly slashed with switchblades on a busy street) are outright bizarre.
* MonsterOfTheWeek: Some of the most awesome Kaijin in the ''Franchise/MetalHeroes'' franchise appear in this show.
* {{Mooks}}: Jahmal's Jamars.
* NobleDemon: Black Beet
* OneWingedAngel: [[spoiler:Jagul turns into her "Destruction-God" form, fusing herself with various destroyed monsters, as well as a few villains from ''Janperson'' and ''Blue SWAT''; it takes Super Blue Beet, [[Series/BlueSWAT Hyper Shou's]] [[GatlingGood [=DrumGunner=]]], and Janperson's Flash Cannon, and being DraggedOffToHell by Bill Goldy to defeat her.]]
* OmnicidalManiac: [[spoiler:Gaohm plans to use the Jamahl Hole to destroy the Earth in order to summon Saint Papilia so he can capture her to gain {{immortality}}.]]
* OutOfTheInferno: Pulled by the B-Fighters in episode three, when walking out of a destroyed building.
* PoweredArmor: The B-Fighters' Insect Armor.
* PowerTrio
* SuperStrength: One of the powers given to the B-Fighters by their armor
* {{Synchronization}}: Whenever Shadow hurts Takuya, or vice-versa, they each feel the pain.
* TransformationTrinket: Handheld devices called the B-Commanders.
* YouHaveOutlivedYourUsefulness: [[spoiler:Jagul pulls this on Goldy and Queen in the finale.]]