Baku Ōmori, a sixth-grader at Aibo Academy, is the strategic cornerstone of Team Balle du Soleil and childhood companion to Gao Mikado and Kuguru Uki. As the team’s deck architect, he crafts and refines card decks to harmonize with each member’s combat style, prioritizing personal compatibility over rigid control—a direct rejection of his ex-mentor Retsu Omori’s manipulative methods. After Retsu joins the antagonistic Disaster faction, Baku commits to dismantling his former teacher’s ideology through ethical deck-building, proving trustworthiness trumps coercion.

Prone to comedic distraction when hungry, his concentration wanes without regular snacks, often interrupting tense moments or emotional exchanges. His boisterous clashes with Gao never fracture their mutual respect, while his bond with Kuguru simmers with unacknowledged romantic tension. Shared blushes during a Link Attack—where their monster avatars mirror their unspoken feelings—underscore this subtle dynamic.

Baku’s tactical genius shines in critical tournaments, engineering specialized decks to counter foes like Kyoya Gaen’s precision or Dragon Drei’s brute force. He devises pivotal workarounds, such as circumventing Tasuku Ryuenji’s Distortion Punisher!! technique, securing hard-fought victories. His growth from a fiery idealist to a measured strategist emerges through rejecting Retsu’s teachings, crafting independent countermeasures, and navigating team disputes with newfound patience.

A tinkerer at heart, he disassembles gadgets to satisfy his analytical curiosity, mirroring his meticulous deck deconstruction. Though non-combative, his loyalty anchors the team: he mediates Gao’s impulsiveness, bolsters allies during crises, and maintains unity during the World Buddy Cup’s pressures. Early friction over deck adjustments evolves into collaborative trust, epitomizing his arc from stubborn enthusiast to adaptable leader. Through technical ingenuity, unwavering principles, and relatable flaws, Baku drives both his team’s triumphs and the narrative’s exploration of integrity’s role in competition.