He is 12 years old in the first season, 15 in New Vestroia, 16 in Gundalian Invaders, and 17 in Mechtanium Surge. In the beginning he is ranked #121, and by episode 39, he is ranked #1, and has become ranked #4 or under in episode 6 of Mechtanium Surge. Shun Kazami — The former 1st ranked Bakugan brawler but after Masquerade showed up, he moves down to 6th, then back up to 5th after defeating Komba, then 2nd and ultimately to 3rd by the end of the first series.
He is 13 years old, has black hair, which is tied into a long ponytail, and wears a purple jacket. He is a master of Bakugan and co-created the rules with Dan. He is also Dan's childhood best friend. Shun is a loner, a boy of very few words, but yet is willing to help his friends at almost every turn. He is a Ventus brawler and he approaches Bakugan like a ninja. He lives with his grandfather, who used to be a famous ninja warrior, who once expected Shun to follow in his footsteps instead of playing Bakugan.
His Guardian Bakugan is a Ventus Skyress, whom Shun received from his sick mother. Choji 'Marucho' Marukura — He loves to play Bakugan, but is fonder of creating strategies rather than just using brute force. He used to be very obedient to his parents just because he wanted to please them, but that changed when he met the Brawlers and Preyas. He now has no regrets for the past, realizing that he only wanted to make his parents happy. He is an Aquos battler. His guardian Bakugan is his Aquos Preyas, which, later in the series, is revealed to have a special evolution, allowing him to burp up his two twin brothers, Preyas Angelo, who resembles an angel, and his brother, Preyas Diablo, who resembles a devil, and this allowed Marucho to not only keep Preyas in his original form, but his 'brothers' as well. Runo Misaki — A 12-year-old tomboy who loves playing Bakugan against skilled people so she can show off.