Ten years after the Jamahl Empire fell, a new threat, the Melzard tribe, emerges. At the revamped Earth Academia called Cosmo Academia, Takuya Kai and Guru work on a new generation of Insect-Powered Powered Armor suits. When the Melzard launches their first attack, two of the suits are immediately entrusted to Kengo Tachibana and Ran Ayukawa. The third is soon entrusted to Ordinary High-School Student Kouhei Toba. With the new team in place, the Melzard's schemes for Earth have reached a dead end.
The New Generation B-Fighters:
- Kouhei Toba/B-Fighter Kabuto: The Hero; an Ordinary High-School Student who becomes involved in the fight against evil.
- Kengo Tachibana/B-Fighter Kuwaga: Big Lancer; a student initially bitter with Kouhei for taking the mantle of B-Fighter Kabuto instead of him. However, he does warm up to our hero.
- Ran Ayukawa/B-Fighter Tentou: Smart Chick; she is so involved with technology that she is naive on natural matters.
Our heroes are soon joined by:
- Mac Windy/B-Fighter Yanma: A Funny Foreigner from New York, very much Sanguine.
- Julio Rivera/B-Fighter Genji: A Peruvian archaeologist, love interest for Ran, who taught her to experience the beauty of nature. Played by legendary suit actor Seiji Takaiwa, in one of his only face roles.
- Li Wen/B-Fighter Min: A Chinese elementary schoolteacher and Technical Pacifist.
- Sophie Villeneuve/B-Fighter Ageha: A French violinist and love interest for Kouhei; responsible for wakening the Astral Saber.
- Mother Melzard: The Big Bad
- Dinosaur Warrior Raija: The Saurian-Armored dragon.
- Deep Sea Fish-man Dezzle: Raija's fish-armored brother and arch-enemy.
- Insect Swordswoman Miola: The Insectoid-armored Dark Chick.
- B-Crushers: The Psycho Rangers:
Recurring Metal Hero tropes include:
- By the Power of Grayskull!: "Cho Juko!" ("Super Heavy Shell!")
- Humongous Mecha: The heroes get assistance from two giant Kojin ("Shell Gods"), Kabuterios and Kuwaga Titan.
B-Fighter Kabuto provides examples of the following tropes:
- Bee Afraid: Beezack's armor motif.
- But Not Too Foreign: Except for Mac (played by the American Reuben Langdon,) all the Sixth Rangers are played by Japanese actors. Sophie's actress is half-Mexican, not that you can tell.
- Crossover: The first B-Fighters appear to aid our heroes for some episodes.
- HeelFace Turn: Kuwaga Titan joins the good guys in the finale in order to battle Mother Melzard's final form.
- Japanese Beetle Brothers: B-Fighter Kabuto and B-Fighter Kuwaga, like their predecessors, are a Type A.
- Power Trio: Kabuto, Kuwaga and Tentou, like their predecessors.
- The Psycho Rangers: The B-Crushers, opposites of the four New B-Fighters