Season 1

Episode 11
Grandpa's Got a Brand New Bakugan
Marucho and Runo realize that the combined strength of the Battle Brawlers doesn't match up to Masquerade's power. Without Dan's knowledge, they visit Shun to try and convince him to join the team. Shun's Grandpa tries to send them away but Shun challenges them to a Brawl. If Marucho and Runo beat him, then he'll join. If not, he walks away...

Episode 12
Bakugan Stall
Alice realizes that she may have a connection to the mysterious Hal-G, but can't get up the courage to tell the rest of the Brawlers. Meanwhile, Dan recalls the last battle that he had with Shun and we discover why Shun decided to leave the game for good. Shun's mother gives him a very special Bakugan, "Skyress," to watch over him.

Episode 13
Just For The Shun Of It
Masquerade has been destroying kids' Bakugans all over the world and the Brawlers need to put a stop to it. Reluctantly, Dan joins Runo and Marucho in another attempt to recruit Shun. When they arrive at Shun's home, Masquerade is already there! They can't believe that Shun is on Masquerade's side. Dan accepts the challenge of a battle and together with his Bakugan Drago, goes up against Shun and Masquerade. Will Shun send Drago to the doom dimension or will his old friendship with Dan convince him to turn on Masquerade?

Episode 14
The Story Of Vestroia
Lured by an invitation to celebrate their world class rankings, five of the top ten Bakugan players gather at a mysterious mansion. There they meet Masquerade and the evil Bakugan "Naga." They are put under a spell to take Dan and the other Battle Brawlers out of the picture. Meanwhile, Alice confesses that she believes her grandfather Michael had something to do with the destruction of Vestroia. The brawlers decide to visit Dr. Michael's lab and find evidence of what happened to him. But there are still many unanswered questions...

Episode 15
Duel In The Desert
Dan and his friends head off to the middle of nowhere to visit Julie who lives near the Bukugan Valley. Rumor has it that this is the place where the Infinity Core is. Our heroes want to find it and figure out what they can do to stop the Core from spreading its evil power around the world. In essence, shut down Hal-G and Masquerade and ultimately Naga. After a short trek, they find it, but before they can continue their investigation, they meet up with Julie's friends Billy and Komba. These two challenge the Brawlers to a battle. The twist is, both Billy and Komba are aligned with Masquerade and they want to send the Brawlers' Bakugan to the Doom Dimenison. The battle heats up as Shun and Julie enter the battle. Both Billy and Komba are ace Bakugan players with incredible gaming skills and it looks like they're about to take the victory. Suddenly, Shun sacrifies his Fairy Bakugan to save Julie's Golem and win the battle.

Episode 16
No Guts No Glory
While the Bakugan Battle Brawlers desperately try to search for the Infinity Core in Bakugan Valley, they can't help but feel sorry for their teammate, Julie. She discovered that her childhood friend Billy had joined up with Masquerade and the news devastates her. However, Shun has other things on his mind. He believes that someone close to the Brawlers may be a spy and they are feeding information to Masquerade. So he sets a trap to test his theory and he lures Chan Lee, one of Masquerade's gang, out into the open. Chan Lee is the third best Bakugan player in the world and she challenges Dan to a battle. They fight a fierce match but in the end Dan and Drago are victorious. The team is elated over Dan's win but Shun realizes he was right about a spy being in their camp all along. It turns out he's a mysterious figure, who runs the Brawlers' website, who goes by the name of Webmaster Joe.

Episode 17
BFF Best Freinds Forever
We briefly meet Klaus Von Herzon, the number two world ranked Bakugan player. He collects Bakugan, and obviously has his eye on Marucho's Bakugan, Preyus. Meanwhile, our heroes are exhausted from searching for the Infinity Core and are disheartened by their lack of success. Marucho and Preyus whip up a quick meal, which picks up everyone's spirits. Dan suggests asking for info on the Infinity Core on their website, despite the risk. Everyone eventually agrees, and soon they have a lead! They all fly to Germany and wind up in a huge castle, which belongs to none other than Klaus Von Herzon! Klaus challenges Marucho and Preyus to a Brawl, holding the Infinity Core for ransom. It turns out that Klaus is working for Masquerade, and a long Battle culminates in Preyus being sent to the Doom dimension! Marucho is shattered at the loss of his friend and we are left seeing Preyus floating in the void of the Doom Dimension.

Episode 18
Evolution Revolution
Runo and Marucho were chasing Klaus through the castle when they mysteriously found themselves in a strange wing. After searching around, they discover a computer in the dungeon that takes them to a strange hi-tech control room. All over the walls are digital displays of rankings of all Bakugan players throughout the world. And then... poof! Without warning, Runo and Marucho are facing off against Masquerade's muscleman Julio in battle! Dan realizes that Runo isn't strong enough to take on Masquerade's minion by herself, so he joins the battle. It rages on with Julio easily outpowering them. The situation is desperate and it isn't until Drago starts his "evolution process" that they tie the score and eventually win. Now the Brawlers are on a quest to evolve one of their Bakugan before Masquerade finds the Infinity Core or... it's all over!

Episode 19
Julie Plays "Hard Brawl"
Dan, restless for action, loses his cool at a brunch meeting when he tries to grill a distraught Marucho about Masquerade's secret hideout location. Runo tries chilling the situation but her jealousy over Julie ends up getting in the way, isolating herself and forcing Dan and Julie to go at it alone to find Billy; a childhood friend of Julie's who's under Masquerade's control. The trail leads to Germany where Julie insists on battling Billy solo, much to Dan's disapproval. But Dan eases off when he sees that Julie's skills appear to be giving her the upper hand. But of course, killer looks are deceiving and it turns out to be a dirty set up, one that nearly sends Julie into the Doom Dimension. Luckily, Julie has her own game plan, proving that winning isn't everything when loosing a friend is at stake.

Episode 20
A Little Help From My Freinds
Dan and his pals are flying into the Bakugan Valley to continue their quest for the Infinity Core when Dan pushes his weight around a little too much and everyone gets upset with him... especially Runo and Shun. In fact, Shun has had enough of Dan and decides to leave, believing that he's better off as a lone gun in his attempt to seek out and destroy Masquerade. As Shun ventures away from our heroes, Alice catches up to him. She's worried. But before she can convince him to return to the others, Shun is confronted by Komba, a cocky little kid who's been recruited by Masquerade. Komba challenges Shun to a battle. At first, Shun is simply annoyed, but then decides to take the wanna-be Brawler on. In no time, Shun beats him soundly and just as the battle ends, Dan shows up to apologize to Shun for being such a hot head. In the end, Shun and Dan both learn a valuable lesson about friendship!