Shun Kazami, heir to the wealthy Kazami International Holdings technology empire, sought independence from family expectations by traveling alone to North America to pursue Bakugan battling. Initially reserved, overly serious, and favoring formal attire like blue suits, he approached battles with mature strategic thinking focused intensely on winning, yet not ruthlessly. Witnessing the Awesome Brawlers online led him to join as their fourth member, partnering initially with Aquos Hydorous. While loyal, Shun struggled with interpersonal connections, gradually learning to prioritize camaraderie over individual victory, a shift solidified when he exposed his cousin Masato's attempt to sabotage the team.

During the *Geogan Rising* crisis where Bakugan entered prolonged hibernation after battling Sabrus, Hydorous remained inactive. Shun then discovered Aquos Sharktar on "Junk Island" in Vestroia, making it his primary Guardian Bakugan for the season. He investigated destabilized Earth-Vestroia connections causing Bakugan to vanish post-loss and damaging battle arenas, aiding in deploying new mobile gate technology. This involved encounters with chaotic Geogan Bakugan like Sharktar and Fenneca. Shun collaborated consistently with the Awesome Brawlers to counter threats from antagonists like Gregorius Reed and Viloch, focusing on healing hibernating Bakugan and repairing planetary rifts, though specific individual battle outcomes were less documented than before.

He retained the Baku-Gear "Wings of Aquos" created in *Armored Alliance*, and his transition to Sharktar highlighted adaptability in partnerships without compromising effectiveness. Shun maintained his calm, analytical battle style but showed increased openness to teamwork during the dimensional crises. His arc concluded with a reaffirmed dedication to protecting Earth and Vestroia alongside a solidified bond with the Awesome Brawlers.