Gao Mikado anchors multiple anime seasons as protagonist, trained in Mikado-style Aiki-jujutsu at his family dojo while attending Aibo Academy's elementary division. He channels deep admiration for his late brother Yota Mikado—creator of the "Mighty Sun Fighter" comic—by inverting his coat to reveal a sun symbol, adopting this heroic identity to defend others from bullies. This drives his core mission to protect the vulnerable and prevent descents into darkness, persisting even when betrayed.

After transferring to Aibo Academy three years prior, initial isolation ended when classmates invited him to dodgeball, forging lasting friendships. His personality merges fierce justice with a hot temper, sparking aggressive or reckless actions that occasionally worsen conflicts. Unwavering trust and swift forgiveness form exploitable weaknesses. A childhood obsession with martial arts victory once blinded him to sportsmanship, causing opponent injuries—a flaw resurfacing during early Buddyfights like his one-turn win against Rouga Aragami, where recognizing this destructive competitiveness spurred redemption.

Character evolution unfolds through bonds with three primary buddy monsters:
- **Drum Bunker Dragon (Fang Slade Terrestrial XIV)**: His first buddy, enabling flight via golden hoverboard Buddy Skill. Their bond fractured when Drum left for training, draining Gao's Buddyfight passion until Kazane Fujimiya's fervor reignited it.
- **Dragon of the Sun, Bal Dragon**: His second buddy. Bal's poisoning by Doctor Gara triggered Gao's "Dragon Force of Anger"—marked by red energy and wing-like projections—later evolving into "Style of Impact".
- **Demon Lord Dragon Batzz (Barlbatzz Dragoroyale the First)**: His final buddy, tied to the Thunder Empire. Their partnership risked "Heroic RRoD" (soul-body separation from Impact overuse) and achieved "Draconification," fusing into armored forms like "Dragonificator Gao".

Abilities encompass martial arts and supernatural "cat-like eye" powers:
- **Future Force**: Initially involuntary during rage or peril, materializing Buddyfight cards. He gained control during Gaen Cup finals.
- **Evolution**: Enhances Impact cards (e.g., evolving "Gargantua Punisher" into "Roaring Slash!! Gargantua Punisher!!"), reverting if shared.
- **Transformations**: Beyond Dragon Force, he mastered "Future Force DX" (combining all forms) and "Thunder Emperor's Fangs" for multi-world deck tactics.

His journey spans key arcs:
- **Early Buddyfights**: As a novice, he defeated veterans like Tasuku Ryuenji and Tetsuya Kurodake through unorthodox strategies. Forming Team Balle du Soleil for the ABC Cup exposed vulnerabilities like leaving his center unprotected.
- **Key Conflicts**: Rescuing Kiri Hyoryu from Sengoku Academy ignited battles against the "Four Demon Generals." Gao inspired positive change in allies like Genma Todoroki and Rouga Aragami but inadvertently fueled Drum and Kiri's inadequacy, pushing Kiri toward dark powers.
- **Later Seasons**: Joining Buddy Police in *Hundred*, he wielded Hero World and Crimson Battler decks. *Triple D* featured his World Buddy Cup partnership with Bal. *X* saw him represent Dragon World in World Buddy Masters with Batzz. His final arc culminated in the GGG Cup before relocating to America.

Gao married Paruko Nanana, fathering sons Yuga and Haru Mikado. His legacy endures in *Buddyfight Ace* where Yuga becomes protagonist, with Gao's influence echoing through family and the Mighty Sun Fighter symbol.