Bakugan

which aired in other countries before Japan. The fourth and final season, Mechtanium Surge, was never broadcast in Japan and instead aired in Canadian and U.S. markets. The Bakugan franchise are co-produced from Spin Master and Sega Toys, with animation by TMS Entertainment and Nelvana Animation.

A reboot series called '''Baku Tech! Bakugan''' which featured the characters from the manga of the same name aired on TV Tokyo from April 7, 2012 to March 30, 2013. It was followed by a sequel series called '''Baku Tech! Bakugan Gachi''' which ran from April 6, 2013 to December 28, 2013.

Plot
In Battle Brawlers the parallel world of Vestroia, a power-hungry Bakugan (a small marble magnetic sphere which when thrown on a gate card turns into a highly strong and powerful warrior) named Naga decides to absorb the energy of the two opposing cores that preserve the balance and peace in Vestroia. However he absorbed too much power and energy found within the Silent Core, the source of negative energy. The Infinity Core, the source of positive energy had been absorbed by Wavern.

The story centers on five friends who find metallic cards which have fallen from the sky or to be more precise, Vestroia itself. They name themselves the Bakugan Battle Brawlers and consist of seven children: Dan, Shun, Runo, Marucho, Julie, Alice, and later Joe. Together they learn more about the origin of the Bakugan, Vestroia, the game involving them, and the battle against Hal-G, Masquerade and Naga.

In New Vestroia, Dan, Marucho, and Shun are called to the newly restored Vestroia to stop an evil group known as the Vexos who invaded it. They allied with three new brawlers named Mira, Ace, and Baron in order to stop the Vexos from taking over New Vestroia, and possibly, the whole universe.

In Gundalian Invaders Dan, Marucho and Shun get caught up in a war between two different alien factions in another universe, and teaming up with three of the top brawlers from Neathia. Fabia, Ren and Jake, in order to stop the evil Gundalian Protectors, the Twelve Orders from destroying Neathia, and possibly, Earth.

In Mechtanium Surge First Arc: Bakugan Interspace gets messy when Dan learns his battling directly threatens Earth. Drago's exposure to Code Eve has infused him with incredible power, causing him to unwittingly release Mechtogan Zenthon, a new mysterious entity that wreaks havoc whenever Drago battles! While Dan attempts to regain control over Drago’s new powers, an insidious enemy builds an army of "Chaos Bakugan" engineered for total world domination! Will Dan be able to get a hold of Drago's power before its to late?

Second Arc:Bakugan City is off to a peaceful start now that humans have communed with the Bakugan from New Vestroia. This comes to an abrupt end, however, when four Mechtogan who have broken free from their Bakugan start terrorizing the world. Not only that, but some creep called Wiseman has appeared with ancient Bakugan called the Nonets. It's now up to the Battle Brawlers to stop Wiseman, the Nonets, and the Mechtogan's greatest weapon: Mechtavius Destroyer!

in Battle Planet The season follows the adventures of Dan Kouzo and the AO (the Awesome Ones), the first kids on Earth to bond with the mysterious alien creatures known as the Bakugan. The storyline revolves around friendship, battling, and competition. Near the end of the season Dan and the AO try to defeat Tiko.

in Armored Alliance Dan kouzo and the AO (the Awesome Ones) Discover Baku Gear (please add more info)