Mitsunari Tokugawa, 13th head of the Tokugawa clan and descendant of Tokugawa Mitsukuni, presides as "Noble Elder" over Tokyo Dome’s Underground Arena, a no-rules battleground attracting fighters of varied disciplines. His encyclopedic grasp of martial arts, honed through decades of spectating, fuels a near-sociopathic obsession with orchestrated violence. He manipulates match dynamics to escalate brutality—permitting weapons in Musashi Miyamoto’s duel against Retsu Kaiou, an act he later regrets following Retsu’s death. Yet he imposes limits, forbidding cannibalism during Pickle’s bouts and shielding fighters from fatal excess. Moments of vulnerability surface in his grief over Doppo Orochi’s near-fatal injury and self-reproach for Retsu’s demise. His cunning emerges in subduing Yuujirou Hanma via blue-whale-strength tranquilizers, a rare feat. Political and military alliances, including ties to Japan’s prime ministers and General Gerry Strydum, secure the arena’s clandestine existence. Kureha Shinogi merges surgical precision with combat prowess, touting his “athlete-style” physique as superior to traditional martial arts. Driven by narcissism and contempt for fighters, he confronts Baki Hanma to validate medical knowledge’s supremacy, only to face humbling defeat. His surgical skill shines in saving Doppo Orochi by manually restarting his heart. Post-loss humility softens his arrogance, prompting altruistic acts like cautioning Jack Hanma against steroid abuse. His relationship with younger brother Koushou shifts from condescending control to uneasy respect, climaxing during their Maximum Tournament clash. After manipulating brackets to fight Koushou, Kureha endures a blinding strike, self-operates mid-match to restore vision, then surrenders, acknowledging his brother’s resolve—a pivot from icy dominance to grudging kinship. Koushou Shinogi’s “Cord-Cutting” karate targets nerves and tendons, embodying technical lethality. An early Underground Arena bout against Baki Hanma sees him cripple Baki’s right side before defeat erodes his confidence, worsened by Hector Doyle’s dishonorable explosive tactics. The Maximum Tournament forces a reckoning with Kureha, mirroring his battle to escape his brother’s shadow. Initially paralyzed by childhood trauma during their fight, Koushou lands a decisive blow that blinds Kureha, compelling his surrender—a hard-won step toward self-assurance. Subsequent struggles, like confronting Yuujirou Hanma’s rampage, expose lingering insecurities. His principled combat style and rigid ethics contrast starkly with the arena’s ruthless pragmatism, framing him as both foil and counterpart to Baki and Kureha.