Marucho Marukura starts as a wealthy, intellectually gifted member of the Battle Brawlers, specializing in Aquos. Initially obedient to his parents, joining the team sparks significant personal growth, helping him embrace his past and forge his own path. His first partner Bakugan is Preyas; Preyas's temporary loss to the Doom Dimension forges deeper resolve and loyalty in Marucho. Preyas later evolves into Angelo/Diablo Preyas, remaining a key partner alongside the original Preyas. In New Vestroia, Marucho aids the Resistance against the Vestal invasion. Vexos capture Preyas early on, leading Marucho to partner with Elfin, a Bakugan trained by Preyas. He strategically defeats Vexos members Mylene Farrow and Shadow Prove, testing this partnership. Volt Luster temporarily defeats and captures him before his rescue. Elfin evolves into Minx Elfin, and Preyas returns after liberation from Prince Hydron's palace. Marucho demonstrates leadership by housing the Resistance at his mansion and developing Battle Gear like JetKor for Drago. During Gundalian Invaders, Marucho's technological expertise shines as he creates and oversees Bakugan Interspace, a global battling platform where he ranks #3. His primary partner shifts to Akwimos, though he temporarily uses captured or digital Bakugan like Ventus Buz Hornix. He mentors Jake Vallory, gifting him Subterra Coredem. Emotionally, he struggles with betrayal by Ren Krawler but reconciles after a confrontational brawl, revealing his Battle Gear Gigarth. Serving as a Castle Knight for Neathia, he devises critical military decoy strategies against Gundalian forces, earning recognition from Queen Serena. He participates in the final battle against Emperor Barodius and Phantom Dharak before returning to Earth. In Mechtanium Surge, Marucho partners with Aquos Infinity Trister (later replaced by Aquos Radizen and temporarily Subterra Roxtor). Delegating Bakugan Interspace administration leads to unchecked expansion and chaotic elements like BakuNano abuse. He collaborates with Shun Kazami to stabilize Drago's power surges, creating their joint Mechtogan Duomechtra. He battles threats like Team Anubias/Sellon and Zenthon, a destructive Mechtogan spawned unintentionally by Drago. During the conflict with Mag Mel, Marucho contributes strategic support against Mechtavius Destroyer. A temporal reset via the Current of Time prevents the deaths of allies, including Preyas and Elfin, who had perished defending New Vestroia. Throughout his journey, Marucho evolves from a sheltered tactician to a resilient leader and innovator, maintaining core traits of loyalty and intellectual prowess while adapting to interdimensional threats. His Bakugan partnerships reflect mutual growth, particularly with Preyas, whose return after the temporal reset implies continued collaboration.