Marucho Marukura began as an affluent, obedient child adhering strictly to parental expectations. His journey with the Battle Brawlers catalyzed personal growth, balancing self-expression with familial respect. Serving as the team's strategic mind, he acted as a walking encyclopedia, employing analytical, data-driven tactics in battles—though occasionally overrelying on pre-battle planning during spontaneous combat. His loyalty and dependability intertwined with underlying anxiety, manifesting as cautious decision-making and vigilance toward friends' safety. In *Bakugan Battle Brawlers*, he bonded with Guardian Bakugan Aquos Preyas after its accidental arrival at his housewarming party. Their partnership faced crisis when Klaus von Hertzon banished Preyas to the Doom Dimension, compelling Marucho to pursue Klaus through a portal for rescue. Preyas later evolved into Angelo/Diablo Preyas via unique multiplication, allowing Marucho to wield both forms simultaneously. During a psychological trial by Sacred Soldier Frosch, Marucho confronted a manifestation of his former obedient self, reconciling it as part of his identity. He secured seventh place globally by the season's end. Transitioning to *New Vestroia*, Marucho aided the resistance against Vestal invaders alongside Dan Kuso and Drago. Separated from captive Preyas, he encountered Elfin in a jungle. After a joint battle against Mylene Farrow—where Shun Kazami ensured their victory—Elfin became his temporary Guardian Bakugan, later evolving into Minx Elfin via Frosch's energy. Marucho mastered the Vestal brawling system, liberated Bakugan in Gamma City, and infiltrated Prince Hydron's palace to free Preyas and Tigrerra. He founded Bakugan Interspace as a global training arena, deploying a digital Akwimos after Preyas and Elfin remained in New Vestroia. During *Gundalian Invaders*, as Bakugan Interspace's manager and global third-ranked brawler, he trusted Ren Krawler, who betrayed the team by unleashing a virus within Interspace. Marucho countered by creating a backdoor escape for trapped brawlers. He adopted a physical Aquos Akwimos, supplied by Fabia, for battles in the Gundalia-Neathia war. In *Mechtanium Surge*, Marucho partnered with Aquos Trister (Infinity Trister) as his primary Guardian Bakugan. He maintained oversight of Bakugan Interspace but delegated administration to automated systems, inadvertently enabling malicious actors like card dealer Dylan. He utilized Trister to stabilize arenas during Drago's power fluctuations and confronted threats like the rogue Mechtogan Zenthon. Throughout all arcs, his attire consistently featured blue or aqua tones reflecting his Aquos attribute, later updated with orange or Subterra accents.