Medabots—powerful robots granted artificial intelligence through special "medals"—serve at the whims of their owner. They are more commonly used in "Robbatling," a popular combat sport where two medabots face off against one another. In its professional form, Medafighters use their Medabots to qualify for the World Tournament and fight amongst the elite to gain the title of champion. Elementary schooler Ikki Tenryou has just gained his first Medabot: Metabee, an outdated model with no medal. Fortunately, however, Ikki manages to find a medal in the nearby river; but when Ikki places it into Metabee's head, the latter starts to exhibit strange behaviour. Short-tempered and rebellious, he refuses to obey Ikki's orders. However, to climb the ranks to the World Tournament, Ikki and Metabee must first learn to work together, no matter how difficult the prospect may seem…

Mysterious cards came down from the sky one day. Capable of summoning powerful creatures from another dimension, they became the centerpiece of a new game called Bakugan. The game gained instant popularity among children and teenagers, with the best of them competing in a worldwide ranking. Meanwhile, war for domination over Vestroia, the homeland of Bakugan cards, rages on. Invaded by the White Dragon Naga and his servants, the Doom Beings, the realm becomes increasingly destabilized. Dimensions begin to merge and many Bakugan players come to realize that their pastime is not merely a game. Danma Kuusou, one such Bakugan player, intends to become the World Ranking's leader someday. However, during one of his fights he experiences a vision of a clash in Vestroia. The fight suddenly moves to Earth, where Danma comes into possession of a talking, mighty fire Bakugan, Pyrus Dragonoid. He soon gets dragged into the conflict, and together with his Bakugan Brawlers team, must traverse the dimensions and restore balance in a ravaged world.

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.

The series follows pre-teens Dan Kouzo, Shun Kazami, Wynton Styles, Lia Venegas, and their dog Lightning. They are known as the "Awesome Ones" and make videos on the website ViewTube. Eventually, they stumble across a race of battling biomechanical creatures called Bakugan. They soon befriend the Bakugan and begin to battle each other with them, all while defending their neighborhood from thugs who use the Bakugan for malicious purposes. (Source: Wikipedia)