When Sybel, a freelance reporter, discovers a military plane crash, she is thrilled by the prospect of getting her hands on the latest inside scoop. However, she is unaware that the plane was carrying two top-secret prototype android assassins who will stop at nothing to destroy their target. As the military frantically tries to clean up its mess, Sybel races against time to find and protect the robots' targeted victim—all while documenting the military's misconduct—before it is too late.

After the final downfall of the rogue Bakugan Naga, peace was brought back to Vestroia. With the help of Danma Kuusou, his companion Pyrus Dragonoid, and other Battle Brawlers, the Infinity and Silent Cores were combined and the realm was recreated. However, New Vestroia will not be given any respite as humanoid alien invaders, the Vestals, arrive and conquer the Bakugan world in one fell swoop. Armed with a fearsome machine capable of restricting Bakugan into their ball forms, they aim to enslave the race as a form of entertainment. Now, the only force standing in their way is the Bakugan Battle Brawlers Resistance—a group of humans, Bakugan, and Vestals who oppose the idea of annihilating a sentient race. Led by Danma, they must venture into enemy-occupied New Vestroia and repel the invaders, to assure the survival of the entire world. [Written by MAL Rewrite]

Amane Todoroki is a young girl who is straightforward but also unthinking. She will try her very best in everything and say, "I don't know how to answer you if you ask me whether this can be done. I just believe it can. If not, then nothing will get started!" She easily gets stuck in her thinking, but she can also get easily moved at something small and start crying.

Twelve-year-old Linn Youki loyally supported his father when the world laughed at the scientist for saying that Earth was about to be invaded from outer space. But Linn did not expect to become personally involved--until he met Takoro, the strange young "deputy sheriff" from another world who was on the trail of notorious space criminals. There were only four Kurodako Brothers, but they plotted to use their alien science and natural shape-changing powers to become the secret masters of Earth. With Takoro's help, Linn became the mighty super-hero, Muteking, to foil their schemes. There is plenty of action and laughs in this light-hearted comedy-drama about a roller-skating costumed hero, his friendly but bumbling alien partner, a gang of klutzy would-be world conquerors, a beautiful police chief, an obsessed scientist, a sarcastic dog, an officious flying saucer, and others. This unusual but appealing cast of characters will charm viewers' hearts while it amuses them.